Can Reminders Promote Regular Pro-Environmental
Behavior? Experimental Evidence from Peru
Hanna Fuhrmann-Riebel Ben D’Exelle Kristian Lopez Vargas
Sebastian Tonke8 Arjan Verschoor 1l
Abstract
Pro-environmental behavior, suclr as recycling, often needs to be regular to be effective, and interventions to encourage behavioral change may therefore need to be repeated: yet, little evidence exists on the optimal time pattern and frequency of suclr repeated interventions. To fill this gap, we investigate the impact of mobile text reminders on households’ recycling behavior in urban Peru by randomly varying the exposure length and continuity of reminders. We find that reminders increase both the likelihood that households start to recycle and the frequency of recycling among households that already did so before the intervention. Tire effects are stronger when reminders are repeated over a longer period. Our findings suggest that both limited attention and habit formation matter for recycling behavior, and that low-cost mobile text reminders can effectively support regular pro-environmental behavior.
Keywords: Reminders, limited attention, habit formation, recycling, Peru JEL Classification: C93, D83, D90, D91, Q53, Q58
1.		Introduction
Increasing global waste accumulation poses a serious threat to ecosystems, biodiversity, and human health, and contributes significantly to environmental pollution and climate change (UNEP, 2024). While the waste crisis requires a collective response from both the public and the private sector, it also demands a permanent shift in households’ regular behavior; household recycling behavior is a paradigmatic example of this much-needed behavioral change. Weeldy kerbside collection of recyclables, typical in many places around the world, requires people to organize their waste in tire household in advance, collect materials throughout the week, and finally put the bags outside their house on the same day each week. Recycling remains limited in many low- and middle-income countries: while in Western Europe around 55% of municipal solid waste is recycled, in South America only around 5% is (ibid.). Consequently, large amounts of waste end up in dumpsites, affecting people’s health and the environment (Kaza et al., 2018).
Following the existing literature, in this paper we distinguisli two critical behavioral aspects to understand what can be done to increase recycling behavior. First, people may fail to implement their recycling intentions because of limited attention (Datta and Mullainathan, 2014; Karlan et al., 2016; Tiefenbeck et al., 2018). Humans’ limited cognitive capacity means that they can only pay limited attention to recycling, which requires substantial organization (such as separating recyclables, putting them in a bag, placing the bag on the street on the correct day and time, etc.). Second, habit formation may play a role: once people have recycled a few times, they may form a routine/habit in recycling practices, and the barrier of limited attention may weaken or disappear.
The issue of limited attention might be addressed by sending timely reminders that bring the specific behavior "to the top of mind” (Karlan et al., 2016). However, it is unclear how effective reminders are when aiming to change regular behavior (as opposed to one-time or irregular actions). We may need to repeat reminders to overcome limited attention repeatedly. Yet. the effectiveness of reminders may also decrease with repetition clue to habituation (Rankin et al., 2009), i.e., we may experience a weakened behavioral response due to repeated treatment. If so, interrupting the series of reminders (and possibly restarting it after a pause) may recover the behavioral response to tlie treatment. In addition, reminders may need to be repeated for habits to be formed, which, once established, will reduce the need for further reminders. However, here again it is a priori not clear how long people need to be treated for habits to be formed (Charness and Gneezy, 2009; Allcott and Rogers, 2014; Royer et al., 2015; Byrne et al., 2024).
This leads to two critical questions: 1) whether reminders can increase recycling, and 2) what time pattern of reminders can promote repeated recycling most effectively. Regarding the second question, we are especially interested in understanding i) whether a longer series of reminders is more effective than a shorter series, and ii) whether a continuous series of reminders is more effective than an interrupted and restarted series to encourage regular recycling.
To answer these questions, we conducted a field experiment with households that are registered in a recycling program in urban Peru. Many households do not recycle regularly, even thougli they voluntarily signed up for the recycling program. This suggests that there may be a gap between their intention to recycle and actual recycling behavior, and possibly also a lack of routine and habit formation. Assuming both could be addressed with the help of reminders, we sent mobile text reminders to households with varying exposure lengtlr and continuity to test their effect on recycling.
We collected data on houseliolds’ recycling behavior over 12 weeks by accompanying the recycling trucks collecting the bags on their daily routes. Having the addresses of registered households allowed us to identify which households put a recycling bag on the street in which week, without needing to contact thenr. This approach has key advantages, as it avoids interference with the intervention (people were not made aware of our study) as well as the limitations of self-reported data.
While the first three weeks of our study period serve as a baseline measure (weeks 1-3), the subsequent nine weeks (weeks 4-12) constitute our intervention period where households are randomly assigned to one of four groups: i) a control group that does not receive any reminders, ii) a group that receives weekly reminders continuously during the whole intervention period, weeks 4-12 (continuous treatment), iii) a group that receives reminders only during the first three weeks of the intervention period, weeks 4-6 (interrupted treatment), iv) or a group that receives reminders for the first three weeks, weeks 4-6, and for the last tliree weeks, weeks 10-12, of the intervention period, witlr a three weeks’ pause in between during which no reminders are received (restarted treatment).
Our main findings can be summarized as follows. First, we show that reminders are generally effective at increasing recycling behavior: weekly reminders in the first three weeks of the intervention increase the likeliliood of recycling in all treatment groups compared to the control group. This initial effect seems to be mainly driven by households that already recycled at baseline. Second, we find that the effect becomes stronger if reminders are continued for another three weeks. Third, we observe that households that did not yet recycle at baseline might need a longer series of reminders to start recycling than households that already recycled before. Fourth, we find suggestive evidence that both limited attention and habit formation matter for recycling behavior and tlie effectiveness of reminders.
We contribute to tire existing literature in three ways. First, there is a growing yet still limited literature on the effectiveness of repeated reminders in the context of regular behaviors, for example, concerning gym attendance (Calzolari and Nardotto, 2017; Muller and Habla, 2018), regular savings (Rodriguez and Saavedra, 2019; Milkman et al., 2025) or the reuse of plastic bags (Essl et al., 2021) and recycling (Chong et al., 2015). These regular behaviors stand in contrast to infrequent or one-time actions, such as attending a doctor’s appointment. As outlined above, making this distinction is important, as beyond limited attention, habit formation can matter as well for repeated behaviors and the responsiveness to reminders. We contribute to this literature by generating new evidence on the role of the exposure length and continuity with which reminders are sent, since we deploy treatments witlr long (continuous), short (interrupted), and paused (restarted) reminder exposure. In contrast to previous studies, our design allows us to compare the effects of interrupted reminders (i.e., post intervention effects) to the effects of reminders that are continued during the same time period, or restarted, which extends evidence of looking at post-intervention persistence effects only, without having a comparison group. A recent paper by Byrne et al. (2024) takes a similar approach by varying tlie treatment exposure duration in the context of real-time in-tlre-shower feedback on water usage in Australia. With our novel design, we can generate important new insights on the role of limited attention and habituation as well as their potential interplay for regular (recycling) behavior, as outlined in more detail in our conceptual framework.
Second, we contribute to the so far limited evidence on the effectiveness of reminders on household recycling behavior in particular. 7 While recycling behavior constitutes a behavior that requires regular, repeated action, it is also characterized by the fact that it mirrors a collective action problem tliat requires individual action for collective benefit (see, e.g., Fuhrmann-Riebel et al. (2024)). This distinguishes tlie behavior from other regular behaviors studied in the reminder literature, whiclr generate direct individual benefits, such as gym attendance or personal savings. Moreover, its measurement is considerably more labor-intensive than that of other behaviors studied in the literature so far (e.g., gym attendance, savings, or energy consumption), which can be measured digitally. The "hard to measure” nature of recycling behavior is a main reason why most studies on recycling behavior rely on self-reported data, whiclr has several critical limitations (Huffman et al., 2014). There are few studies that test tire impact of reminders on actual recycling behavior. Essi et al. (2021) found a positive effect of weekly renrinders in the form of stickers and flyers on the reuse of plastic bags (i.e., plastic waste reduction) in the context of weekly food delivery boxes in Switzerland. Chong et al. (2015), whiclr conres closest to our study, also focused on the effect of reminders on household recycling behavior in a recycling program in Peru. The authors did not find any significant impact of mobile text reminders on households’ recycling activity. The ineffectiveness of their intervention was probably due to the lack of recycling equipment withirr the household (concretely, the absence of recycling bins), wlrich, according to the authors, was the main obstacle for households to recycle. Witlr an observation period of six weeks, their study period was also considerably shorter than ours. Our main contributiorr to this literature is that we do find that reminders can significantly increase households' recycling activity, supporting the authors’ assunrption that lacking recycling equipment was the main reason why their intervention failed. Also, with a considerably longer study period, we are able to provide novel evidence on the role of habit formation in recycling practices and how this might affect the effectiveness of reminders, which previous studies could not.
Third, we contribute to the growing body of researcli on behavioral interventions in developing countries where institutional and infrastructure constraints as well as different attitudes and responses to such interventions can play essential roles. Recent metaanalyses on behavioral interventions find that only a small share of the current evidence comes from developing countries and is concentrated in a few policy areas (Hummel and Maedche, 2019; Mertens et al., 2022). Other reviews in behavioral development economics emphasize that experiments in developing countries often find strong patterns of attentional and self-control frictions, and that the underlying institutional and physical infrastructure as well as market failures might amplify or dampen the impact of nudges (Kremer et al., 2021). This is especially crucial for recycling behavior as very little academic work has been conducted on the topic in developing countries even though these are the regions that suffer most from inefficient waste management and the resulting environmental consequences (Chong et al., 2015). Our paper thus adds important new insights on the effectiveness of behavioral interventions in developing countries for a highly relevant behavior on which the evidence so far is very limited. A great benefit of our intervention is that sending SMS reminders has low implementation costs, whiclr is especially important for studies conducted outside a high-income country context where financial resources are often limited.
The rest of the paper proceeds as follows. Section 2 presents the design of the experiment, including the conceptual framework, treatnrents, hypotheses, and implementation. In section 3 we report the results, while section 4 concludes the paper.
2.		Design
2.1.		Conceptual framework
Before presenting our experiment, it is important to conceptualize how we understand the role of reminders for recycling behavior. Recycling imposes an immediate, tangible hassle (rinsing containers, sorting waste, dragging a bin to the curb), but its environmental benefits arrive slowly in the future and favor a diffuse collective. Households that voluntarily enroll in a municipal program display an underlying pro-social cooperative motive. Yet, they remain exposed to cognitive frictions and biases that often derail low-stakes, cooperative tasks, suclr as recycling. They might be present-focused and might devote their scarce attention to whatever is most salient at the moment. With present bias, each collection cycle resembles a soft deadline that can always be met “later tonight or tomorrow”; witlr limited attention, the critical nronrent carr pass urrrroticed. The joint presence of procrastination and forgetting is damaging because these frictions might enhance one another.
If these negative psychological forces are overcome and the individual is effectively reminded to recycle (for the first time, or in a higher frequency and volume), a new habit could be formed, and the need for the reminder might disappear. Psychology offers a view of how behavior repetition might translate into durable change. Habits, in the sense as articulated by Wood and Neal (2007), are automatic responses to familiar cues that bypass deliberation once a context-response link is replicated often enough. Lally et al. (2010) observe that automaticity grows quickly at first and then plateaus, reaching 95 percent of its long-run level after two months, on average. However, there is a substantial heterogeneity across individuals and behaviors, and in most cases, habits are difficult to form.
A series of reminders delivered early in the morning of the pickup day, the intervention we study in this paper, addresses tire negative behavioral elements described above and is a potential contributor to habit formation. However, the length of tlie exposure is likely to play a crucial role. A burst of reminders may trigger meaningful gains in tlie first weeks, yet might not generate enough exposure for a new habit to be established. Also, the reminder’s efficacy is unlikely to be uniform over time. Early in an intervention, households might suffer from behavioral inertia or sit below a salience threshold required for action so that additional prompts may show increasing returns toward tire propensity of the desired behavior. Over time, however, a countervailing force may emerge. Repeated messaging might create “habituation,” a well-documented decrement in responsiveness to unchanging stimuli (Rankin et al., 2009); people could become desensitized to the reminders as they receive more of them.
It is essential, however, to recognize that reminders might sustain recycling even without forging true habits. By making recycling top-of-mind exactly when the weekly deadline looms, messages can keep attention consistently above the threshold needed for action; Byrne et al. (2024) shows that such an “attention stock” accumulates gradually, dissipates slowly, and can be re-activated after a pause. This perspective highlights several potential choke points — perception of the cue, valuation of the trade-off, execution of the task — at whiclr interventions may fail: messages may arrive too early and invite procrastination, repeat so often that they fade into background noise, or leave the perceived physical effort of filling the recycling bag untouched.
Our experimental desigir takes tlrese insights to tire data by asking tlrree sequential questions. First, do renrinders delivered early on the day of collection increase the probability that a household sets out its recycling at all? A null answer would indicate that attentioir is not the biirdiirg constraint, or that present bias overwhelnrs any gains from salience. Second, conditional on sonre positive effect, does the cumulative duration of exposure matter? Comparing a three-week to a nine-week sequence allows us to test whether continued sahence translates into higher compliance or slower decay. Third, does inserting a pause midway through, a nine-week reminder schedule raise effectiveness relative to sending the messages continuously? Evidence that this paused arm outperforms the continuous long exposure would validate the role of desensitization and the possibility of attention-stock reactivation.
Important recent papers study interventions in otlier domains that share our theoretical underpinnings, underscoring that the temporal profile of a reminding cue shapes both its immediate impact and its persistence. Byrne et al. (2024) shows in residential water use that longer salience campaigns flatten the decay of conservation once nudges stop, consistent witlr an attention stock that accumulates gradually and dissipates slowly. Gravert arrd Olssoir Colleirtine (2021) find that doubling a free-trial period for public transport, rather than issuing a one-off social-norm nressage, led to lasting increases in riderslrip, signaling that sheer exposure lengtlr can seed new routines wlren intrinsic incentives are weak. Complementing these duration effects, Tiefenbeck et al. (2018, 2019) demonstrate that real-tinre shower feedback achieves sizable and immediate resource savings by overconring sahence bias without attenuation of the treatment. Together, these studies higlrliglrt multiple patlrways through which repeated or well-tinred interventions achieve persistence, and they help motivate our experiment’s focus on disentangling the roles of cumulative exposure, temporal spacing, and desensitization.
2.2.		Treatments
To address our research questions, we randomly assign individuals to one of four treatments in a between-subjects design. The four groups consist of one control group and three treatment groups (see Table 1). None of the groups receives any reminders in the baseline period. From period 2 onward, we vary tire time pattern of reminders, creating four groups as follows:
•		Control (TO): no reminders
•		Continuous treatment (Τ1): reminders over all nine weeks; long exposure
•		Interrupted treatment (Τ2): reminders only for the first three weeks; short exposure
•		Restarted treatment (Τ3): reminders for the first three weeks and for the last three weeks with a three-week: pause in between; paused exposure
Table 1: Study design overview
	Baseline		Intervention			
	Period 1	Period 2	Period 3	Period 4		
	wl w2 w3	w4 w5 w6	w7 w8 w9	wlO wll	wl2	
Control (ΤΟ)						
Continuous (Τ1)		X	X	X	X	X	X	X	X	X	
Interrupted (Τ2)		X	X	X				
Restarted (Τ3)		X	X	X		X	X	X	
Notes: The table provides an overview of the study design, including three weeks of baseline period followed by nine weeks of intervention period. "x" indicates the weeks in whicli households received a reminder in the different treatment groups. The 12 weeks of the study ran from mid-June to mid-September 2021.

All treatment groups receive tire same treatment during the first three weeks of the intervention period, period 2. In the subsequent three weeks, period 3, only tlre continuous treatment group (T1) continues to receive reminders, while both Τ2 and Τ3 are interrupted and tlius not distinguishable from each other up to this point. Only during the last three weeks, period 4, the restarted treatment group (Τ3) receives reminders again while the interrupted treatment group (Τ2) remains discontinued, so that all three treatment groups differ.
The treatment variation based on blocks of three weeks was chosen, given the irregular nature of households’ recycling behavior. From pre-COVID data (until February 2020) from the municipality, we know that only a few households recycle regularly every week (or even more than once a week, if the bags are collected twice). Most households recycle irregularly, and rather every second or third week, on average. Some households that are registered do not recycle at all. We do not have data on households’ recycling behavior afterwards, as the municipality had to stop all measurements due to the pandemic. However, during a one-week pilot that we did in the beginning of May 2021, only 13% of all enrolled households recycled in that week, confirming the irregularity in recycling behavior from pre-COVID times.
The treatment message of the mobile text reminder contained a friendly greeting from the municipality and a reminder for people to put their recycling bags outside on that day. We also gave people a number they could call in case of doubts and referred to the social media channels of the municipality. The formulation of the reminder message was chosen carefully based on joint discussions with tlie municipality. All households that received a reminder received the same treatment message. We present the message here in English, while the original message was formulated in Spanish:
IT’S RECYCLING DAΥ: The Municipality of Miraflores reminds you that the recycling truck will pass by your house today. Don’t forget to take out your recycling material! Please find more information on the municipality’s social media or by contacting us at [number].
2.3.		Treatment comparisons and hypotheses
In this section, we explain how we will compare recycling behavior across the treatments, and present the hypotheses that we pre-registered. We start witlr a comparison of recycling behavior in period 2. In this period, all treated households receive a weekly reminder. We expect that this will address people’s limited attention to the recycling program, while most will not have formed any recycling habits yet. Therefore, we expect the reminders in this period to increase recycling activity, as outlined by Hypothesis 1.
Hypothesis 1 (Period 2): Recycling in the treatment groups (T1, Τ2 and Τ3) is higher than in the control group (TO).
In period 3, two treatment groups (Τ2 and Τ3) stop receiving reminders. We expect that some households might develop a habit relatively fast and keep recycling in period 3. As a result, we expect that recycling will remain higher in each of tlre treatment groups, relative to the control group. At tire same time, we expect recycling to be smaller in the interrupted treatment groups Τ2 and Τ3 relative to the continuous treatment group Τ1. This might be driven by households that would benefit from a longer series of reminders to start recycling, and households that formed some recycling habits in the first period, whose habits weaken without further reminders. This is summarized in Hypothesis 2.
Hypothesis 2 (Period 3): i) Recycling in the continuous treatment (Τ1) and the interrupted treatments (Τ2 and Τ3) is higher than in the control group (TO); ii) Recycling is higher in the continuous treatment group (Τ1) than in the interrupted treatments (Τ2 and Τ3).
In period 4, the treatment groups are separated into a continuous, interrupted and restarted treatment group. We expect that recycling remains higher in all three treatment groups Τ1, Τ2 and Τ3 (thanks to recycling habits in period 2, supported by the reinforcement of another series of reminders in period 3 and period 4) relative to the control group. As recycling habits might weaken over time, recycling will be higher in tlie continuous treatment (Τ1) than in the interrupted treatment (T2). In addition, under the conjecture of desensitization/habituation playing a role, we expect recycling to be higher in treatment Τ3 than in treatment Τ1. The restarted reminders in treatment Τ3 will capture people’s attention better than tlie continuous reminders in Τ1, since a pause in tlie reminders will make their resumption stand out, so that the reminders will be more effective when restarded. We summarize these predicted differences in Hypothesis 3.
Hypothesis 3 (Period 4): i) Recycling in each treatment group (Τ1, Τ2 and T3) is higher than in the control group (TO); ii) Recycling is higher in the continuous group (Tl) than in the interrupted group (T2); iii) Recycling is higher in the restarted treatment group (Τ3) than in the continuous treatment group (Τ1)
2.4.		Implementation
2.4-		1- Setting
For this study, we worked togetlier with a municipal recycling program in tlre capital city of Peru, Lima. Managing solid waste in Lima is a huge challenge. Around 10 million people live in the country’s largest city. It is estimated that around 8,468 tons of garbage are generated daily in Lima, of which only 4% is recycled (WWF, 2018). Municipalities are responsible for coordinating recycling activities at tlre Irousehold level in Peru. Some municipalities in Lima have established their own recycling program, in whiclr households can participate voluntarily and free of charge. Tins is also the case for the municipality of Miraflores, an upper-middle-to high-income neighborhood in Lima, with whiclr we collaborated for tlris study. Households participating in tlre recycling progranr need to separate their recyclable nraterials at Ironre, collect them in a separate bag, and deposit this bag on the street on a specific clay of the week, so that it can be collected by a recycling truck.
The district of Miraflores consists of 14 zones, based on whiclr the recycling progranr is organized. Recycling bags are collected on weekdays in tlre mornings and afternoons, and on Saturdays in the mornings. There are always two recycling trucks operating in two different zones at the same time. In some zones (six out of 14), the bags are collected once a week; irr the other zones (eight out of 14), they are collected twice a week, always on the same day(s) at approximately the same tinre. The municipality inforrrred residerrts about tlre collection days across different zones when liouseliolds registered for the program. Thus, paying attention to this specific day and tinre to place the recycling bags on the street is crucial for people to participate successfully.
Sample
There are 7.183 households officially registered in the recycling program (end of Marcir 2021). The district of Miraflores contains single-family houses as well as apartment buildings and other multiple dwelling units. It is therefore possible that two households are registered witlr the same address in the progranr if they live in the sanre building.
In our study, we only include houselrolds that are registered witlr a unique address. We do so, as we want to link household recycling behavior to specific individual households. If there is more than one household registered in an apartment building, it is impossible to identify to which household the collected recycling bags belong, as recycling bags are usually deposited in a shared space and then taken outside on tlre street by the caretaker or doorman of the building. Of the 7,183 houselrolds registered in tlre recycling progranr, 3,480 had a unique address.
Wlren Irouseholcls register for the recycling progranr, tlrey are asked to give a phone number. Households can decide whether they register witlr a landline or a cell phone nunrber. Sirrce sending nrobile text reminders requires access to mobile phone numbers, we focus on those households of wlriclr mobile phorre nunrbers are available. This is the case for 1,392 households of the 3,480 households that are registered witlr a unique address. This is the sample that we will use in our study.
Data collection
To keep track of households’ recycling behavior, we accompanied the recycling trucks that are responsible for collecting the recycling bags orr their daily routes over a total time period of 12 weeks, from mid-June to nrid-Septenrber 2021. Enumerators followed the recycling trucks by bike. The recording of households’ recycling behavior was done through audio recordings via headsets. Enumerators were instructed to record the following details: street name, house number, house type (single family house or apartment building/other multiple dwelling unit), and number of bags. The audio recordings were transcribed to an Excel sheet afterwards. Regular quality checks were applied to both data collection in the held and transcriptions of the audio recordings. Enumerators were not aware of the treatment assignment, i.e., they did not know which households had received reminders and which had not.
The reminders were sent to households in the early mornings of the collection days via mobile text through a Peruvian provider. This was adjusted based on the different zones and respective collection days (so that, for example, households from a zone where the bags are collected on Wednesdays received the reminders on Wednesdays in the early morning). We sent reminders to all households only once a week, regardless of whether the bags were collected once or twice a week: in the respective zones. In zones witlr two collection days per week, the reminders were sent in the nrorning of the first collection day of the week.
3.		Results
3.1.		Descriptives
Table Α.1 in Appendix A provides a detailed overview of household characteristics by treatnrent group, including the zone, sign-up year, and house type. Zones range fronr 1 to 14, sign-up years from 2015 to 2021. We distinguish the different house types between single-family houses, apartment buildings or other nrultiple dwelling units, and unknown house types. The table further shows whether households recycled during the baseline period. Balance tests confirm that these household characteristics are balanced across treatment groups.
Since sign-up years go back: to 2015, we decided to focus our analysis primarily on households with a recent sign-up year (2018 or later), as there is a risk that some of the respondents who registered a long time ago might not respond to our treatments, mainly for two reasons. First, people might have moved from the district and are thus unable to participate in the recycling program. Second, people might have changed their phone numbers and be unable to receive our mobile text reminders. Ideally, we would have been able to remove those respondents from our database. However, as the municipality does not update their data base with contact details on a regular basis, it was not possible for us to identify these respondents. A second-best approach is therefore to focus on households with a more recent sign-up year, as tlie risk of reaching an invalid household is smaller among recently registered houselrolds. This assumption is supported by Table A.2 in Appendix A, which confirms that the percentage of households that recycled at least once during the whole intervention period and during the baseline period is higher anrong those that signed up nrore recently.
In our main analysis, we will focus on Irouseholds that signed up in 2018 or later, whiclr reduces our total sanrple size from 1,392 to 898 houselrolds. We provide a detailed overview of Irousehold characteristics by treatment group as well as balance tests for those houselrolds witlr a recent sign-up year separately in Appendix A (Table A.3). We can confirm that household characteristics are also balanced across treatnrent groups irr the sub-sample of recently registered houselrolds. To test the robustness of our results, we will also report all results using the full sanrple (see Appendix Ε).
It should be noted that there was a week of public holiday after the first three weeks of the intervention period, i.e., between weeks 6 and 7 of our study period, where no recycling service was in place and thus no renrinders were sent and no data could be collected. Therefore, the whole implementation period was extended to 13 weeks, while the analysis focuses on the 12 weeks of our study period.
The same was the case for tlre Monday of week 11, wlrere again no recycling service was in place due to a public Iroliday, and tlrus no renrinders were sent and no data could be collected for that day. In this case, no additional week was added, so that week 11 contains one day less in our analysis.
3.2.		Treatment effects by period
The main outcome variable of our analysis is a binary variable equal to one if a household recycled at least once per period of three weeks, zero otherwise. We focus on recycling behavior per period rather than week: because of the irregular nature of households’ recycling activity, as explained in Section 2.2. Histograms on households’ recycling frequency in Appendix B confirm that liardly any household recycled every week in the baseline period.
We start witlr a visual presentation of the recycling activity over the individual periods 1 to 4. Figure 1 traces period-by-period the share of houselrolds that recycled at least once. In sub-figure la, we pool the three treatment groups together to conrpare thenr with the control group. While the recycling rates are similar during tlre baseline period (at around 19%), we observe a clear treatnrent-control difference once the intervention begins: in periods 2 and 3, the percentage of treated houselrolds that recycle is about 5 p.p. higher than in the control group, with largely non-overlapping confidence intervals (CIs). Although the recycling activity in all groups dips in period 4, the treatment CI band remains above the control recycling rate.
In sub-figure lb, we pool groups that have been treated identically in the respective periods (that is, groups that share the same reminder exposure profile). Because all treatment groups are identical in period 2, in this period, the red CI is the same as in the previous panel. From period 3 onward, tlie designs diverge. Households that keep receiving weekly reminders (T1, orange) raise their recycling rate to 24% (compared to roughly 18% in the control group), whereas those whose reminders are paused (purple, Τ2&Τ3) still show a higher recycling rate at 21%, yet now exhibit a CI that mostly overlaps with the control group. In period 4, when tire restarted treatment group (grey, Τ3) resumes the messages, all treatments are different. While the recycling activity remains higher in all treatment groups, their CIs now mostly overlap with the control group, altliougli less so for tire interrupted treatment.
In sub-figure lc, we show the three treatment arms separately for each period. We see that in period 2, all treatment groups exhibit a higher recycling rate than the control group (between 21-22% versus ~16%). In period 3, recycling rates remain higher in all treatment groups compared to the control group, altliougli the CI of tlie restarted group mostly overlaps witlr that of the control group. In period 4, as shown in sub-figure lb, all treated groups still have recycling rates above the control group, but all CIs largely overlap. We conduct the formal statistical tests of treatnrent effects within the regression analysis.
The analyses presented below in Table 2 are the regressions associated witlr sub-figure 1b. We focus on tlrose regressions irr our main analysis as they mirror tlre treatnrent exposure of our irrterventioir most accurately. As an additional robustness check, we present panel regressions associated witlr all sub-figures of Figure 1 irr Table F.2 of the Appendix F. For our nrairr analysis, we estinrate a regressiorr of the following form:
Y = Bo + BT + B2Xt + u (1)
witlr Y being a binary variable equal to one if a houselrold recycled at least once irr the respective period, zero otlrerwise. T is a set of indicator variables for tlre treatnrent groups, using the control group as reference. X includes controls for households’ baseline recycling activity (i.e., whether they recycled at least once irr period 1), the house type (whether it is a single-family Irouse as opposed to a nrultiple dwelling unit or an unknown house type), and indicator variables for the different enumerators. We estinrate regressions witlr OLS.19 To adjust for nrultiple hypothesis testing, we calculate sharpened q-values for tlre seven estinrates preserrted in Table 2 (Benjanrini et al., 2006; Anderson,
19A robustness check using logistic regressions is presented in Appendix D.l. All results are robust to using logit specifications.

(a) All treatments vs. control

• Control (TO) · All treatments (Τ1&Τ2&Τ3)

Figure 1: Proportion of households that recycled at least once per period, by treatment

(b) Pooling treatments witlr identical exposure

• Control (TO) · All treatments (Τ1&Τ2&Τ3) Continuous (Τ1)	· Interrupted & Restarted (Τ2&Τ3)
• Interrupted (Τ2)	· Restarted (Τ3)

(c) Eacli treatment separately

• Control (TO) · Continuous (Τ1)
• Interrupted (Τ2)	· Restarted (Τ3)

Notes: The figure shows the proportion of households that recycled at least once per period in the control group and in the different treatment groups over the whole study period, focusing on households witlr a recent sign-up year (> 2018). Sub-figure la compares all treatment groups pooled together witlr the control group; sub-figure lb pools treatment groups that have iderrtieal exposure as of each period in the horizontal axis; and sub-figure 1c compares the control group with eaclr treatment group separately. Vertical lines and whiskers denote the 95% CI. N(T0) = 216, N(T1&T2&T3) = 682, N(T1) = 219, N(T2&T3) = 463, N(T2) = 236, N(T3) = 227.
2008).
We first look at the effect of all treatment groups pooled together over the whole intervention period. The regression results reported in column (1) of Table 2 confirm that the treatment-control difference in recycling rates is 4.7 p.p. and statistically significant (p-value = 0.015; q-value = 0.048).
We next look at eacli of the intervention periods separately according to our treatment exposure. Column (2) of Table 2 shows that in period 2, the difference in recycling levels between tlie treatment groups and the control group is 5.4 p.p. and statistically significant (p-value = 0.039; q-value = 0.070), supporting our hypothesis H1.
Table 2: Treatment effects on whether households recycled at least once, by period
	Period 2-4
(1)	Period 2
(2)	Period 3
(3)	Period 4
(4)	
All treatments (T1&T2&T3)	0.047**	0.054**			
	(0.019)	(0.026)			
Continuous (Τ1)			0.083***	0.042	
			(0.030)	(0.028)	
Interrupted & Restarted (T2&T3)			0.034		
			(0.025)		
Interrupted (Τ2)				0.049*	
				(0.028)	
Restarted (Τ3)				0.019	
				(0.027)	
Predicted Probability Control (TO)	0.158***	0.160***	0.172***	0.141***	
	(0.017)	(0.023)	(0.020)	(0.018)	
Adjusted R2	0.355	0.341	0.393	0.332	
Observations	2694	898	898	898	
Notes: The table reports OLS regressions with dependent variable equal to one if a household recycled at least once during the respective period. All regressions include a control for households’ binary baseline recycling activity and tlie house type, and use fixed effects for enu- nierators. Only households included that signed up in 2018 or later. Robust standard errors in parentheses; standard errors clustered at the household level in column (1). ***, **, * indicate significance levels at 1. 5, and 10%, respectively. Exact p-values as well as q-values resulting from multiple hypotheses corrections are presented in the text. Logit regressions arc reported in Table D.l. Panel regression analog is reported in Table F.2. A panel logit regression analog is reported in Table F.4.

We now turn to period 3, where the treatment groups are split between households that continued receiving weekly reminders (continuous treatment, Τ1) and those that did not (interrupted treatment groups, Τ2 and Τ3). As explained above, we continue to pool treatments Τ2 and Τ3 together for this analysis since botti did not receive any reminders during period 3 and are thus technically not distinguishable from each other up to this point. Column (3) in Table 2 confirms that in period 3, the percentage of households that recycled is 8.3 p.p. higher in the continuous group than in the control group (p-value = 0.006; q-value = 0.041). While tlie coefficient of Τ2&Τ3 is positive in column (3) as well, it is not statistically significant. Moreover, when comparing treatment coefficients, we find weak evidence that the coefficient of Τ1 is significantly larger than the coefficient of Τ2&Τ3 (p-value of the two-sided Wald test = 0.065). This indicates that when only looking at period 3, the recycling activity of Irouseholds in the continuous group is significantly higher than that of households in the interrupted groups. We can thus partly confirm our hypothesis Η2, altliougli the positive difference in recycling activity that we observe in tire interrupted treatment groups compared to tlre control group in period 3 is not statistically significant.
Finally, we turn to period 4, where tlie treatment groups are separated into the continuous, interrupted, and restarted group. As seen in Figure 1, tlre recycling activity in period 4 remains higher in the treatment groups than in tlre control group, yet drops in all groups compared to previous periods, and even falls below levels in the baseline period in the case of tire control group. The regressions reported in column (4) of Table 2 confirm that the treatment coefficients are still positive, but not statistically significant. The only exception is the interrupted treatment group, whiclr is statistically significant at tlre 10% level, yet only before adjusting for multiple hypotheses testing (p-value = 0.081; q-value = 0.101). Using a two-sided test that compares the treatment coefficients, none of the differences are statistically significant (p-values are: 0.827 for Τ1 = Τ2, 0.438 for Τ1 = Τ3, and 0.313 for Τ3 = Τ2). In sum, we do not find evidence in support of hypotlresis H3.
In Appendix F, Table F.2, we report the results of the panel regression (see specification Equation 2). Results are largely consistent witlr those irr Table 2. Irr these fully disaggregated exercises, Τ1 has a significant positive effect irr periods 2 and 3 (0.083*** irr OLS vs. 0.087*** in tlre panel regression), and none of the otlrer treatments have any significant impact on recycling behavior irr any period. In particular, the weakly significant effect of Τ2 irr period 4 does not show up in this panel analysis (0.049* irr OLS vs. 0.042 in the panel regression). The combined effect of all treatments compared to the control group renrains significant at the 10% level (periods 2-4: 0.047** in OLS vs. 0.047* in the panel regression, period 2: 0.054** irr OLS vs. 0.054* irr the panel regression).
3.3.		Heterogeneous effects and mechanisms
3.3.1.		Heterogeneity by recycling at baseline
While the previous section presented our main analysis that informed our pre-registered hypotheses, this section provides additional insights regarding heterogeneous effects and the mechanisms behind our effects. The histogram presented in Figure B.1 in Appendix B shows that around 20% of the households irr our sanrple did recycle at least once irr the
Table 3: Treatment effects on whether households recycled at least once, by period - baseline recycling yes vs. no
	Baseline recycling = yes	Baseline recycling = no	
	Period 2-4
(1)	Period 2
(2)	Period 3 (3)	Period 4 (4)	Period 2-4
(5)	Period 2 (6)	Period 3 (7)	Period 4 (8)	
All treatments (T1&T2&T3)	0.107	0.220"			0.028*	0.010			
	(0.069)	(0.087)			(0.016)	(0.024)			
Continuous (Τ1)			0.191”	0.000			0.058”	0.050”	
			(0.095)	(0.109)			(0.029)	(0.024)	
Interrupted & Restarted (T2&T3)			0.051				0.024		
			(0.089)				(0.023)		
Interrupted (Τ2)				0.036				0.048**	
				(0.104)				(0.024)	
Restarted (Τ3)				-0.022				0.023	
				(0.108)				(0.022)	
Predicted Probability Control (TO)	0.590***	0.514***	0.6.52"*	0.606***	0.058***	0.080***	0.061**	0.034**	
	(0.061)	(0.077)	(0.074)	(0.075)	(0.013)	(0.021)	(0.017)	(0.014)	
Adjusted H2	0.018	0.036	0.008	-0.020	0.028	0.010	0.055	0.022	
Observations	516	172	172	172	2178	726	726	726	
Notes: The table reports OLS regressions with dependent variable equal to one if a household recycled at least once during the respective period. Only households included that signed up in 2018 or later. Columns (1)-(4) only include households that recycled during the baseline period; columns (5)-(8) only include households that did not recycle during the baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in columns (1) and (5). Using two-sided Wald tests to compare treatment coefficients gives the following p-values: column (3) p=0.073 for Τ1 = T2&T3: column (4) p=0.740 for Τ1 = Τ2, p=0.839 for T1 = Τ3, p=0.580 for Τ3 = T2; column (7) p=0.211 for T1 = T2&T3; column (8) p=0.938 for Τ1 = T2, p=0.310 for Τ1 = Τ3, p=0.338 for Τ3 = Τ2. , **, * indicate significance levels at 1. 5, and 10%. respectively. OLS regression with baseline recycling as a dependent variable is reported in Table D.2. Panel regression analog is reported in Table F.3.

baseline period, witlr only around 3% recycling every week. Given this heterogeneity, it is interesting to test whether the renrinder effects vary between households that already recycled at baseline arrd those that did not. It is plausible that both types of Irouseholds would benefit fronr renrinders, but irr a different way. For example, households that did not yet recycle at baselirre nriglrt need more reminders to start recycling than Irouseholds that already recycled recently.
Table 3 separates the main regressions by whether houselrolds recycled at least once during the baseline period (period 1). We observe that the predicted probabilities are substantially higher in the left parrel compared to the right panel. This indicates that respondents who recycled at baseline are much more likely to recycle irr eaclr of tire subsequent periods, everr without being treated. Looking at the size of the treatnrent coefficients, we observe that the renrinder effects in periods 2 and 3 are stronger among households that already recycled at baseline. Renrinder effects among households that did not recycle at baselirre are absent in period 2, but do appear irr period 3 witlr the continuous treatment. These findings suggest that households that did not yet recycle at baselirre may need a longer series of renrinders to start recycling, while the immediate effects that we notice in period 2 seenr to be nrainly driven by those households that already recycled before. Comparing the effects of treatment Τ1 and the interrupted treatments (Τ2 & Τ3) in period 3, we observe that their difference is substantial and (weakly) significant in the left panel, but not in the right panel.
In period 4, we find significant positive effects of the continuous and the interrupted treatment anrong houselrolds that did not recycle at baseline, but not anrong Irouseholds that already recycled before. In fact, the effect for baseline recyclers goes from around 20 p.p. to zero. The lack of significant effects among the respondents who recycled in the baseline period may be due to the lower sample size. In Appendix D.2, Table D.2, we report the single specification version of the same table, where we interact the baseline recycling dummy with the treatment indicators. In Appendix F, Table F.3, we report the panel regression analog of the analysis of this subsection. In both cases, the results closely track those reported above.
3.3.2.		Mechanisms
Our conceptual framework argues that reminders might lift recycling through two main psychological mechanisms. The first is limited attention: Irouseholds that intend to recycle often fail to do so because the task never beconres sufficiently salient at the right moment. Recurring reminder nressages nriglit help with this. Tire second is habit formation: repeated recycling might build a routine that could persist even wlren renrinders cease. Several subtleties could accompany these forces. The effect of renrinders could be inrmecliate for sonre individuals, while for others, we might need a longer treatnrent exposure for tlre nudges to start drawing their attention. To probe the evidence on these possible behavioral mechanisms, we focus on behavior in period 2, where every treated household received weekly reminder nressages, and period 3, wliere only tlre continuous treatment (Τ1) received renrinders while the interrupted treatments (Τ2 & Τ3) did not. As discussed above, a public holiday might have affected behavior and collection in period 4, so we focus on the first two post-baseline periods (2 and 3) in this analysis.
Table 4 reports on the effects from a multinomial nroclel that classifies every household into one of four nrutually exclusive states: recycling in neither period (never), only in period 3 (only later), only in period 2 (only early), or in both periods (always). The results of this exercise reveal that the continuous treatment (Τ1) generates a sizable reduction in tlre probability of never recycling across periods 2 and 3 (-15 p.p., in Panel A, Column 1), mainly driven by baseline recyclers who show a strong reaction to the messages (-23 p.p. in Panel B, Column 1). Τ1, in particular, impacts tlie probability of recycling only late (+5.9 p.p. in Panel A, Column 2). Interestingly, this improvement is largely driven by households that were baseline non-recyclers (Panel C, Column 2). In other words, the behavioral response to Τ1 crosses tlie sahence or attention threshold and becomes action only after an extended exposure of six consecutive weeks. There is also weak evidence (at 10% level) that Τ1 raises the probability of recycling in both periods, hinting that some households react to the treatment faster. The fact that Τ1 does not impact recycling only in period 2 suggests that backlash or habituation to treatment are not strong forces in our setting.
The interrupted treatments (Τ2 & Τ3), whiclr received reminders in period 2 and not in period 3, exhibit a different profile of effects. Table 4 shows that they, too, boost the likelihood of recycling at least once (lowering the chance of never recycling by 6 p.p.), and this effect is concentrated anrong baseline recyclers who react to the nressages contemporaneously (Panel B, Colunrir 3, +11 p.p.). Wlren the irudges stop in period 3, the gain vanishes. The probabilities of recycling only in period 3 or in both periods renrain statistically unchanged. In other words, reminder messages irr period 2 create salience, eliciting an inrmediate response fronr baseline recyclers, yet fail to induce persistent behavior.
In sum, the evidence indicates that a lengthy exposure to renrinders first works by overconring linrited attention inrmediately among baseline recyclers, and slowly anrong non-recyclers wlro only start acting after being given enouglr exposure. Briefer exposure triggers only a short-lived contemporaneous response among houselrolds that were already recycling in the baseline period and fails to establislr lastiirg routines. It does not change the behavior of baseline non-recyclers. These patterns associated witlr the effects of the continuous (Τ1) and interrupted treatments (Τ2&Τ3) are mostly consistent witlr our findings in Tables 2 and 3, as well as in the panel regression (Tables F.2 and F.3 in Appendix F).
3.4.		Other analyses
3.4-		1- Treatment effects over the entire intervention period
Next, we look at treatment effects on households’ recycling behavior aggregated over the wlrole intervention period (periods 2-4). This analysis is potentially interesting for policy-nrakers who want to know how nrany renrinders they need to send out and irr what sequence to maximize their effect on recycling behavior.
Figure 2 shows tlre distribution of the total recycling frequency over the whole intervention period, by treatnrent. Specifically, for each period, we count whether a liouseliold recycled at least once, and we take the sum of this count across tire three intervention periods (periods 2, 3, and 4). Tlris means that this variable has a value of 3 if a household recycled at least once in each of tlre tlrree periods. Comparing tlre tlrree treatnrents with the control group in sub-figure 2a, we observe a slight shift to the right (i.e., towards higher recycling frequency) in tlre treatment groups. This suggests that in all treatnrent groups households recycled in more periods, on average, than in the control group over the whole intervention period. Comparing sub-figures 2b and 2c, we observe that this

Table 4: Treatment effects on recycling in period 2 and 3 combined
Recycled in ...	(1) neither ρ2 nor ρ3	(2) only ρ3	(3) only ρ2	(4) ρ2 and ρ3	
Panel A: Pooled sample (N = 898)
Continuous (Τ1)	-0.152***	0.059**	0.040	0.053*	
	(0.045)	(0.026)	(0.025)	(0.030)	
Interrupted & Restarted (Τ2&Τ3)	-0.068**	0.011	0.020	0.036	
	(0.034)	(0.017)	(0.019)	(0.023)	
Predicted Probability Control (TO)	0.859***	0.039***	0.041***	0.062***	
	(0.026)	(0.014)	(0.014)	(0.018)	
Panel B: Recycled at baseline (Ν = 172)
Continuous (Τ1)	-0.233***	0.034	0.049	0.150	
	(0.084)	(0.090)	(0.050)	(0.111)	
Interrupted & Restarted (Τ2&Τ3)	-0.153*	-0.076	0.110**	0.120	
	(0.083)	(0.069)	(0.044)	(0.095)	
Predicted Probability Control (TO)	0.308***	0.175***	0.024	0.494***	
	(0.073)	(0.061)	(0.025)	(0.079)	
Panel C: No recycling at baseline (Ν = 726)
Continuous (Τ1)	-0.076**	0.038**	0.023	0.016	
	(0.035)	(0.019)	(0.024)	(0.020)	
Interrupted & Restarted (T2&T3)	-0.016	0.016	-0.008	0.008	
	(0.026)	(0.012)	(0.018)	(0.016)	
Predicted Probability Control (TO)	0.913***	0.015*	0.041***	0.031**	
	(0.021)	(0.009)	(0.015)	(0.013)	

Notes: Marginal probabilities of a multinomial probit regressions on (1) whetlicr households recycled ncitlier in period 2 nor in period 3, (2) whether households recycled only in period 3, (3) whether households recycled only in period 2. (4) whether Irouseholds recycled at least once in both period 2 and period 3. All regressions include a control for the house type and use fixed effects for enumerators. Tire regressions for tlre pooled sample also include a control for households' binary baseline recycling activity. Only households included that signed up irr 2018 or later. Standard errors in parentheses. , , indicate significance levels at 1, 5, and 10%. respectively. We compare the effect, of ΤΙ and Τ2&Τ3 using two-sided Wald tests, which give the following p-values. Panel A: column (1) p=0.046; column (2) p=0.053; column (3) ρ—0.403; column (4) p=0.562. Panel B: column (1) p=0.168; column (2) p=0.136; column (3) p= 0.279; column (4) p=0.750. Panel C: column (1) p=0.060; column (2) p=0.252; column (3) p=0.136; column (4) p=0.669.
slight shift seems to hold irrespective of whether respondents already recycle at baseline.
To test whether treatment differences are statistically significant, we use an ordered probit regression, combining the four frequency categories as the dependent variable. On the right-hand side, we use the same specifications as in our main regression analysis. Table 5 presents the results for the pooled sample and the two sub-samples. In Panel A, we observe that treatments Τ1 and Τ2 significantly reduce the likelihood of no recycling and increase the likelihood that respondents recycle at any of the three frequencies, relative to tire control group. Using tire predicted probabilities in tire control group as reference, these treatment effects are sizeable. Comparing the treatment effects, we observe that the coefficients of Τ1 are larger in absolute terms relative to treatments Τ2 and Τ3. yet the differences are not statistically significant.
Panels B and C disaggregate the results by baseline recycling. All coefficients go in the expected direction, and suggest sizeable effects. The null of the coefficients in Panel B, however, cannot be rejected, likely due to the small sample size. In Panel C, the effects of the continuous treatment remain highly significant, and are now also statistically different from the effects of the restarted treatment Τ3 at the 10% significance level.
3.4.		2. Intensive margin
So far, we focused on the extensive margin of whether households recycled at least once in a certain period. Yet, there might also be an effect of reminders on the intensive margin of households’ recycling activity. As a first measure of recycling intensity, we look at how often (i.e., the number of weeks) a household recycled per period. Given that each period consists of three weeks, this variable can take the values zero to three. Table D.3 in Appendix D.3 presents regression results with this measure as dependent variable. The analysis sliows that the earlier identified treatment effects are still present, yet more difficult to identify witlr this new specification, in terms of statistical significance. These findings suggest that the treatments are less effective at increasing recycling frequencies beyond once per period. This can also be observed in tlre Iristogranrs presented in Appendix B, where we carr see that very few houselrolds recycle more tharr once per period, even after receiving renrinders.
Splitting up this analysis by Irouseholds that did or did not recycle during tlre baseline period, we find that among households that did recycle at baseline, none of the coefficients are significant (see Table D.4). While this nriglrt be due to the lower sample size of this sub-group of households, the coefficients have the expected positive sign. Anrong households that did not recycle at baseline (see Table D.5), we find support for the previous treatment effects: renrinders increase the frequency of recycling, and this effect is driven by the continuatiorr of reminders in period 3. Again, we observe positive effects among tlris sub-group in botlr the corrtinuous and tlre irrterrupted treatnrent in period 4.

(a) Pooled sample

Total recycling frequency during entire intervention period

(b) Baseline recycling yes

Total recycling frequency during entire intervention period

(c) Baseline recycling no

Notes: Tire figure shows histograms for the total recycling frequency during the entire intervention period (period 2-4). Concretely, it shows in how many of tlre different periods of the intervention period households recycled at least once (from zero to three periods). Only households included witlr a recent sign-up year (> 2018). Sub-figure 2a for pooled sample: N(T0) = 216, N(T1) = 219, N(T2) = 236, N(T3) = 227; sub-figure 2b for households that recycled during the baseline period: N(T0) = 42, N(T1) = 38, N(T2) = 48, N(T3) = 44; sub-figure 2c for households that did not recycle during the baseline period: N(T0) = 174, N(T1) = 181, N(T2) = 188, N(T3) = 183.'

Recycled in ...	no period
(1)	one period
(2)	two periods
(3)	three periods
(4)	
Panel A: Pooled sample (Ν = 898)
Continuous (ΤΙ)	-0.112***	0.067***	0.030**	0.038“	
	(0.043)	(0.018)	(0.012)	(0.015)	
Interrupted (Τ2)	-0.085**	0.036**	0.022**	0.027“	
	(0.041)	(0.018)	(0.011)	(0.013)	
Restarted (Τ3)	-0.044	0.019	0.011	0.013	
	(0.040)	(0.018)	(0.011)	(0.012)	
Predicted Probability Control (TO)	0.812***	0.111“	0.043*”	0.033*“	
	(0.028)	(0.016)	(0.009)	(0.009)	
Panel B: Recycled at baseline (Ν = 172)
Continuous (ΤΙ)	-0.084	-0.056	-0.010	0.150	
	(0.058)	(0.039)	(0.011)	(0.100)	
Interrupted (Τ2)	-0.071	-0.044	-0.006	0.121	
	(0.057)	(0.035)	(0.008)	(0.095)	
Restarted (Τ3)	-0.051	-0.029	-0.003	0.083	
	(0.060)	(0.035)	(0.005)	(0.097)	
Predicted Probability Control (TO)	0.187***	0.240***	0.170*”	0.403*“	
	(0.051)	(0.039)	(0.029)	(0.071)	
Panel C: No recycling at baseline (Ν = 726)
Continuous (Τ1)	-0.077**	0.037“	0.020**	0.019“	
	(0.035)	(0.018)	(0.010)	(0.010)	
Interrupted (Τ2)	-0.049	0.025	0.013	0.012	
	(0.034)	(0.017)	(0.009)	(0.008)	
Restarted (Τ3)	-0.013	0.007	0.003	0.003	
	(0.031)	(0.017)	(0.008)	(0.007)	
Predicted Probability Control (TO)	0.901"	0.062***	0.023"*	0.015*	
	(0.022)	(0.013)	(0.007)	(0.006)	
Notes: Marginal probabilities of ordered probit regressions on whether Irouseholds reeyeled in (1) no period, (2)
one period, (3) two periods, or (4) tlrree periods out of the three periods of the intervention. All regressions include a control for tlre house type, and use fixed effects for enumerators. Tlre regressions for tlre pooled sample also include an indicator variable equal to one, if they recycled at baseline. Only households included that signed up in 2018 or later. Standard errors in parentheses. ,, indicate significance levels at 1, 5, and 10%, respectively.
Comparing the marginal probabilities of IT, Τ2 and T3, respectively, using two-sided Wald tests gives the following p-values:
Panel A: column (1) T1 = Τ2: p=0.508, Τ1 = Τ3: p=0.103, Τ2 = Τ3: p=0.321; column (2) T1 = Τ2: p=0.509, Τ1 = Τ3: p=0.106, Τ2 = Τ3: p=0.324; column (3) T1 = Τ2: ρ=0.509, T1 = Τ3: p=0.108, Τ2 = Τ3: p=0.325; column (4) Τ1 = Τ2: p=0.510, Τ1 = Τ3: p=0.111, Τ2 = Τ3: p=0.325;
Panel B: column (1) Τ1 = Τ2: p=0.781, Τ1 = Τ3: p=0.510, Τ2 = Τ3: p=0.686; column (2) Τ1 = Τ2: p=0.782, T1 = Τ3: p=0.512, Τ2 = Τ3: p=0.685; column (3) T1 = Τ2: p=0.785, T1 = Τ3: p=0.538, Τ2 = Τ3: p=0.690; column (4) Τ1 = Τ2: p=0.781, Τ1 = Τ3: ρ=0.509, Τ2 = Τ3: p=0.685;
Panel C: column (1) Τ1 = Τ2: p=0.465, Τ1 = Τ3: p=0.076, Τ2 = Τ3: p=0.294; column (2) T1 = T2: p=0.466, T1 = Τ3: p=0.080, Τ2 = Τ3: p=0.297; column (3) T1 = Τ2: p=0.468, T1 = Τ3: p=0.089, Τ2 = Τ3: p=0.089; column (4) Τ1 = Τ2: p=0.470, Τ1 = Τ3: p=0.094, Τ2 = T3: p=0.304.
As a second measure of recycling intensity, we focus on tire number of bags a household recycled per period. Table D.6 in Appendix D.4 presents regressions results using the number of bags recycled as dependent variable. Our analysis sliows that none of the treatment effects are statistically significant.
Disaggregating the analysis by baseline recycling, we find again that among households that did recycle at baseline, none of the coefficients are significant (see Table D.7). While this might again be partly due to the lower sample size, it is noteworthy that all coefficients have negative signs. If anything, it suggests that reminders make recycling somewhat more efficient in terms of fewer bags used. Among households that did not recycle at baseline (see Table D.8), we find again that reminders increase recycling as measured by the number of bags recycled, and that this effect is driven by the continuation of reminders in period 3. Also for this variable, we observe significant positive effects among this subgroup in period 4 in both tire continuous and tire interrupted treatment.
4.		Conclusion
In tliis paper, we test whether simple reminder messages can increase the recycling activity of households registered in a recycling program in urban Peru. Even thougli households signed up for the recycling program voluntarily, many do not recycle regularly. This suggests that there may be a gap between tlreir intention to recycle and actual recycling behavior, as well as a lack of routine and habit formation in recycling practices. The reminders aim to bring the recycling program to people’s attention on the day when the recycling bags are collected. This could address tire problem of limited attention, which often hampers people from following through with good intentions and forming habits in desirable behaviors. We study how varying the length of exposure to reminders and their continuity impacts recycling behavior over time and whether it supports habit formation in recycling practices.
To identify the causal effect of reminders, we collect data on households’ weekly recycling behavior over 12 weeks and compare it across experimental treatments that vary the exposure lengtli and continuity of the reminders. We find that reminders are generally effective at increasing recycling. In the first intervention period wliere all treatment groups receive weekly reminders (period 2), recycling increases relative to the control group by 5.4 percentage points. This effect is mainly driven by households that already recycled at baseline, where the series of reminders increases the likelihood of recycling by 22 percentage points.
In period 3, the continuous treatment increases recycling rates even further to 8.3 percentage points above levels in the control group. It also performs (weakly) significantly better than the interrupted treatments. The continuation of reminders maintains recycling among households that recycled at baseline, while recycling drops in this subgroup if reminders are not continued. In this period, we also find that households that did not recycle at baseline start recycling if reminders are continued, which suggests that they need a longer series of reminders to change their recycling behavior.
Wlien looking at households’ recycling activity over the wlrole intervention period, treatment differences become less evident. The continuous and interrupted treatments show a positive effect relative to the control group, and the continuous treatment performs better than the restarted treatment. The difference between the continuous and interrupted treatments, liowever, becomes difficult to distinguish statistically. It miglit be due to a lack of statistical power in period 4, wliere we split up tire treatments, and houseliolds’ recycling behavior was reduced by a public Iroliday and the related traveling of many people. Tiffs is supported by the observation that where we only include periods 2 and 3 (Table 4), we do find strong differences between the continuous and interrupted treatments.
Our results provide evidence that both limited attention and habit formation matter for recycling behavior. Limited attention is supported by the fact that several behavioral responses are contemporaneous witli the start of the messaging. It is further supported by the finding that the continuation of reminders increases the likelihood that respondents start to recycle in period 3, relative to the interrupted treatments. The finding that the interrupted treatments increase the likelihood that respondents only recycle in period 2 (and not in period 3, especially among recyclers) suggests that although their attention is activated, the short lengtlr of exposure did not establislr a firm recycling habit by the time we stop sending reminders. At the same time, we find that respondents who recycled at baseline have a 50% probability to recycle in two consecutive periods, irrespective of wliether we send reminders, which suggests that these respondents have already established firm recycling habits.
Our results have the following implications for policy. First, we show that a simple, low-cost tool in the form of sending weekly SMS reminders can effectively increase households’ recycling activity. Given the low implementation costs and the widespread use of mobile phones, the intervention can be scaled up easily. Second, people who did not yet recycle at baseline might need a longer series of reminders to start recycling. Third, as to people who already recycled at baseline, some of them have already established recycling habits and do not need any reminders, while others benefit from reminders and increase the frequency witli which they recycle. Finally, we do not find evidence for a backlasli in recycling or habituation as a result of our intervention.
We end witli two final reflections. First, the estimated effects of our intervention most likely present a lower bound. As we were unable to check whether the phone numbers that we received from the municipality were still active (or still belonged to the initial owner), it is likely that a proportion of participants never received our reminder messages. Second, we cannot assert with confidence that our intervention period was long enough for the development of permanent recycling habits. It is possible that a longer study period might have led to the development of stronger recycling habits. It may also be that, if recycling habits were formed, they would unravel over time, and a new set of reminders might be needed again. Moreover, habituation to the treatment may eventually occur, whicli would support the stopping and restarting of reminders. Researcli investigating recycling behavior and the importance of reminders in combination with habit formation over a longer time frame would be a promising line of future research.
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Appendix
A.		Balance tests and descriptive overview
Table Α.1: Household characteristics by group - full sample
	Control (TO)	Continuous (Τ1)	Interrupted (Τ2)	Restarted (Τ3)	Total	
Zone	1	29	31	24	21	105	
2	16	19	25	23	83	
3*	21	31	29	19	100	
4*	23	20	25	30	98	
5*	15	12	20	12	59	
6*	14	22	19	16	71	
7	9	9	18	8	44	
8*	13	13	12	10	48	
9	28	25	15	36	104	
10	26	21	25	23	95	
11*	77	58	57	71	263	
12	13	17	15	16	61	
13*	18	25	12	26	81	
14*	46	45	52	37	180	
Sign-up year	2015	2	2	4	0	8	
2016	13	12	8	12	45	
2017	117	115	100	109	441	
2018	16	12	14	15	57	
2019	90	82	85	86	343	
2020	78	90	105	94	367	
2021	32	35	32	32	131	
House type	Single family house	157	152	140	153	602	
Multiple dwelling unit	117	124	135	122	498	
n/a	74	72	73	73	292	
Baseline recycling yes	63	59	65	61	248	
no	285	289	283	287	1144	
N	348	348	348	348	1,392	
Notes: The table shows the number of households per group for different household characteristics. A * behind the zone number means that bags arc collected on two days per week in tlie respective zone, without a star means that, they arc collected once a week. Balance tests using chi2 tests show that household characteristics are balanced across groups: p=0.213 for zone, p=0.839 for sign-up year, p=0.598 for house type, p=0.942 for baseline recycling.

Table A.2: Households that recycled at least once: old vs. recent sign-up years J	0	1.2
	Old sign-up years Recent sign-up years Full sample	
Recycled never (whole study period)
Recycled at least once (whole study period)
Recycled never (baseline period)
Recycled at least once (baseline period)
Recycled never (intervention period)
Recycled at least once (intervention period)	73.89%	69.04%	70.76%
26.11%	30.96%	29.24%
84.62%	80.85%	82.18%
15.38%	19.15%	17.82%
77.53%	71.71%	73.78%
22.47%	28.29%	26.22%	
N	494	898	1,392	
Notes: The table shows the percentages of households that recycled at least once during the whole study period, during the baseline period, and during the intervention period, separated for old and recent sign-up years. Old sign-up years include years 2015-2017 (N-494); recent sign-up years include years 2018-2021 (N=898); the full sample includes all sign-up years from 2015-2021 (N=1,392).

Table A.3: Household characteristics by group - recent sign-up years
	Control (TO)	Continuous (Τ1)	Interrupted (Τ2)	Restarted (Τ3)	Total	
Zone	1	25	20	16	15	76	
2	9	13	16	14	52	
3*	12	22	19	13	66	
4*	18	9	14	12	53	
5*	9	11	13	7	40	
6*	12	12	15	8	47	
7		6	10		26	
8*	7	7	8	6	28	
9	10	14	9	20	53	
10	14	12	17	16	59	
11*	57	47	52	62	218	
12	6	11	10	11	38	
13*	10	7	7	14	38	
14*	22	28	30	24	104	
Sign-up year	2018	16	12	14	15	57	
2019	90	82	85	86	343	
2020	78	90	105	94	367	
2021	32	35	32	32	131	
House type	Single family house	63	55	56	65	239	
Multiple dwelling unit	79	92	107	89	367	
n/a	74	72	73	73	292	
Baseline recycling yes	42	38	48	44	172	
no	174	181	188	183	726	
N	216	219	236	227	898	
Notes: The table shows tlie number of households per group for different household characteristics. A * beliind the zone number means that bags arc collected on two days per week in the respective zone, without a star means that flicy arc collected once a week. Only households included that signed up in 2018 or later. Balance tests using chi2 tests show that household characteristics are balanced across groups: p=0.682 for zone, p=0.896 for sign-up year, p=0.094 for house type, p=0.875 for baseline recycling.
B.		Histograms of recycling frequency per period
Figure B.1: Histograms of recycling frequency during tlie baseline period (week 1-3),
comparing all treatment groups together witli the control group

Notes: The figure sliows histograms for the recycling frequency during tlie baseline period (from zero to three times) in the control group and in the aggregated treatment groups, focusing on households with a recent sign-up year (> 2018). N in the control group (TO) = 216, the treatment groups together add up to Ν = 682.
Figure B.2: Histograms of recycling frequency during period 2 (week 4-6), comparing all
treatment groups together witli the control group

Control (TO)

All treatments (T1&T2&T3)

Recycling frequency in period 2
Notes: The figure shows histograms for the recycling frequency during period 2 (from zero to three times) in the control group and in the aggregated treatment groups, focusing on households witli a recent sign-up year (> 2018). N in the control group (TO) = 216, the treatment groups together add up to Ν = 682.

Figure B.3: Histograms of recycling frequency during period 3 (week 7-9), comparing
the continuous and the interrupted treatment groups witli tlie control group

Control (TO)

Continuous (T1)

Interrupted (Τ2&Τ3)

Recycling frequency in period 3

Notes: The figure shows histograms for the recycling frequency during period 3 (from zero to three times) in the control group and in the continuous and interrupted treatment groups, focusing on households with a recent sign-up year (> 2018). N(T0) = 216, N(T1) = 219, N(T2&T3) = 463.
Figure B.4: Histograms of recycling frequency during period 4 (week 10-12), comparing the continuous, interrupted and restarted treatment groups with the control group

Recycling frequency in period 4

Notes: The figure shows histograms for the recycling frequency during period 4 (from zero to three times) in the control group and in the different treatment groups, focusing on households witli a recent sign-up year (> 2018). N(T0) = 216, N(T1) = 219, N(T2) = 236, N(T3) = 227.

C.		Graphs on weekly recycling behavior
Figure C.1: Percentages of households that recycled per week

(a) All treatments vs. control

— Control (TO) 	All treatments (T1&T2&T3)
	Continuous (T1) 	- ■ Interrupted (T2&T3)
	Interrupted (Τ2)	—	Restarted (Τ3)

Notes: The figure shows the percentages of households that recycled at least once per week in the control group and in the different treatment groups over the whole study period, focusing on households witli a recent sign-up year (> 2018). Sub-figure Chia compares all treatment groups pooled together witli the control group; sub-figure C.lb splits up the different treatment groups based on the treatment variation by periods. N(T0) = 216, N(T1&T2&T3) = 682, N(T1) = 219, N(T2&T3) = 463, N(T2) = 236, N(T3) = 227.

D.		Additional analyses
D.l. Logit robustness check for treatment effects by period
Table D.l: Treatment effects on whether households recycled at least once, by period
(logit)
	Period 2-4 (1)	Period 2 (2)	Period 3
(3)	Period 4
(4)	
All treatments (T1&T2&T3)
Continuous (ΤΙ)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.509”
(0.214)	0.551”
(0.280)	0.858”*
(0.313)
0..397
(0.284)	0.495 (0.320)
0.560*
(0..307) 0.265
(0.313)	
Constant	-3.063*"	-2.945”*	-3.070*"	-3.264***	
	(0.231)	(0.303)	(0.292)	(0.277)	
Pseudo R2	0.308	0.293	0.342	0.309	
Observations	2694	898	898	898	
Notes: The table reports logistic regressions with dependent variable equal to one if a household recycled at least once during tlie respective period. Only households included that signed up in 2018 or later. All regressions include a control for households’ binary baseline recycling activity and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). , , indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.4.
D.2. OLS with interactions with baseline recycling dummy
Table D.2: Treatment effects on whether households recycled at least once, by period -
interactions with baseline recycling yes vs. no
	Period 2-4	Period 2	Period 3	Period 4	
	(1)
BR = yes BR. = no	(2)
BR = yes BR = no	(3)
BR = yes BR = no	(1)
BR = yes BR = no	
All treatments (T1&T2&T3)	0.100	0.027*	0.234**	0.009			
	(0.072)	(0.017)	(0.091)	(0.024)			
Continuous (Τ1)			0.145	0.056*	-0.036	0.049**	
			(0.100)	(0.029)	(0.112)	(0.025)	
Interrupted & Restarted (Τ2&Τ3)			0.055	0.023
(0.092)	(0.023)		
Interrupted (Τ2)				0.010	0.047*	
				(0.106)	(0.024)	
Restarted (Τ3)				-0.018	0.023	
				(0.109)	(0.023)	
Predicted Probability Control (T0)	0.564*"	0.061***
(0.063)	(0.014)	0.490***	0.082***
(0.078)	(0.021)	0.617***	0.066***
(0.075)	(0.018)	0.586***	0.036**
(0.076)	(0.014)	
Adjusted R2	0.358	0.356	0.400	0.338	
Observations	2,694	898	898	898	

Notes: BR = baseline recycling. Tlie table reports OLS regressions witli dependent variable equal to one if a household recycled at least once during tlie respective period, columns (l)-(4). For cadi treatment combination, the table shows coefficients resulting from interactions witli tlie baseline recycling dummy (which can be either yes or no). Only households included that signed up in 2018 or later. All regressions include a control for households’ binary baseline recycling activity and tlie house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual liousehold level. Using two-sided tests to compare treatment coefficients gives the following p-values: for column (3). ΤΙ = Τ2&Τ3 when BR = yes gives p=0.267, and ρ=0.229 when BR = no. For column (4). ΤΙ = Τ2 when RR = yes gives p=0.671, and p=0.913 when BR. = no: for Τ1 = Τ3 when BR = yes gives ρ=0.872, and p=0.337 when BR = no: for Τ3 = Τ2 when BR = yes gives ρ=0.791, and p=0.365 when BR = no. . , indicate significance levels at 1. 5. and 10%, respectively.
D.3. Intensive margin - recycling frequency per period
Table D.3: Treatment effects on how often households recycled per period
	Period 2-4
(1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1VT2&T3)
Continuous (Τ1)
Interrupted V Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.075**
(0.037)	0.057 (0.047)	0.145“ (0.057) 0.072
(0.049)	0.086’ (0.048)
0.091’ (0.049) 0.042
(0.051)	
Constant	0.039	0.058	0.032	0.026	
	(0.034)	(0.043)	(0.043)	(0.034)	
Adjusted R2	0.449	0.476	0.456	0.419	
Observations	2694	898	898	898	
Notes: The table reports OLS regressions with dependent variable how often a household recycled during tlie respective period (never up to three times). Only households included that signed up in 2018 or later. All regressions include a control for households’ baseline recycling activity (never up to tliree times) and tlie liouse type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at individual houseliold level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-valucs: column (3) ρ=0.147 for ΤΙ = Τ2&Τ3; column (4) p=0.922 for Τ2 = Τ1, p=0.422 for ΤΙ = Τ3, p=0.376 for Τ2 = Τ3. ***, **, * indicate significance levels at 1.5, and 10%, respectively. Panel regression analog is reported in Table F.5.
Table D.4: Treatment effects on how often households recycled per period - baseline
recycling yes
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Tl)
Interrupted & Restarted (T2VT3)
Interrupted (Τ2)
Restarted (Τ3)	0.162 (0.153)	0.200 (0.200)	0.335 (0.212)
0.169 (0.199)	0.097 (0.208)
0.090 (0.202)
0.011 (0.226)	
Constant	0.295	0.252	0.384	0.254	
	(0.250)	(0.322)	(0.306)	(0.275)	
Adjusted R2	0.226	0.217	0.226	0.191	
Observations	516	172	172	172	
Notes: Tlie table reports OLS regressions witli dependent variable how often a. houseliold recycled during tlie respective period (never up to three times). Only households included that signed up in 2018 or later; only households that recycled during tlie baseline period. All regressions include a. control for households’ baseline recycling activity (never up to tliree times) and tlie liouse type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at. individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) ρ=0.338 for Τ1 = Τ2&Τ3; column (4) p=0.971 for Τ2 = Τ1, p=0.708 for Τ1 = Τ3, p=0.728 for Τ2 Τ3. s indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.6.

Table D.5: Treatment effects on how often households recycled per period - baseline
recycling no
	Period 2-4
(1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (TI&T2&T3)	0.050*	0.017			
	(0.026)	(0.033)			
Continuous (T1)			0.104**	0.084**	
			(0.050)	(0.037)	
Interrupted & Restarted (T2&T3)			0.041 (0.037)		
Interrupted (Τ2)				0.086**
(0.037)	
Restarted (Τ3)				0.043 (0.033)	
Constant	0.034	0.070**	0.026	0.005	
	(0.023)	(0.030)	(0.032)	(0.019)	
Adjusted R2	0.021	0.003	0.040	0.018	
Observations	2178	726	726	726	
Notes: Tlie table reports OLS regressions witli dependent variable how often a houseliold recycled during the respective period (never up to three times). Only households included that signed up in 2018 or later; only households that did not recycle during the baseline period. All regressions include a control for tlie liouse type, and use fixed effects for enumerators. Robust, standard errors in parentheses; standard errors clustered at. individual houseliold level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.198 for T1 = T2&T3; column (4) p=0.997 for Τ2 = T1, p=0.355 for T1 = T3, p=0.327 for Τ2 = Τ3. ***, **, * indicate significance levels at 1. 5, and 10%, respectively. Panel regression analog is reported in Table F.7.
D.4. Intensive margin - number of bags recycled per period
Table D.6: Treatment effects on the number of bags recycled by households per period
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.035	0.057			
	(0.121)	(0.129)			
Continuous (T1)			0.177	-0.008	
			(0.188)	(0.153)	
Interrupted & Restarted (T2&T3)			-0.052		
			(0.165)		
Interrupted (Τ2)				0.054	
				(0.169)	
Restarted (Τ3)				0.027	
				(0.189)	
Constant	0.254”	0.205	0.300*	0.257*	
	(0.128)	(0.130)	(0.162)	(0.140)	
Adjusted R2	0.459	0.490	0.462	0.422	
Observations	2694	898	898	898	
Notes: The table reports OLS regressions witli dependent variable how many bags a household recycled during tlie respective period. Only households included that signed up in 2018 or later. All regressions include a control for households’ baseline recycling activity (moan of recycled bags) and the house type, and use fixed effects for enumerators. Robust standard errors in parent,hoses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.139 for Τ1 = T2&T3; column (4) p=0.698 for Τ2 = T1, p=0.844 for Τ3 = Τ1, p=0.895 for Τ2 = T3. ***, "1, * indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.8.
Table D.7: Treatment effects on the number of bags recycled by households per period -
baseline recycling yes
	Period 2-4
(1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (T1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	-0.451
(0.575)	-0.124
(0.619)	-0.168
(0.807)
-0.649 (0.762)	-0.918
(0.737)
-0.687
(0.799)
-0.590
(0.937)	
Constant	2.039*	1.171	2.409*	2.547*	
	(1.115)	(1.133)	(1.311)	(1.318)	
Adjusted R2	0.322	0.349	0..327	0.246	
Observations	516	172	172	172	
Notes: The table reports OLS regressions witli dependent, variable how many bags a household recycled during the respective period. Only households included that signed up in 2018 or later; only households that recycled during the baseline period. All regressions include a control for households’ baseline recycling activity (mean of recycled bags) and the liouse type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.448 for T1 = T2&T3; column (4) p=0.744 for Τ2 = Τ1, p=0.697 for Τ3 = Τ1, p=0.915 for Τ2 = Τ3. ' , , ’ indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.9.

Table D.8: Treatment effects on the number of bags recycled by households per period -
baseline recycling no
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (TI&T2&T3)	0.139”	0.096			
	(0.058)	(0.070)			
Continuous (T1)			0.280**	0.204**	
			(0.134)	(0.079)	
Interrupted & Restarted (T2&T3)			0.061 (0.089)		
Interrupted (T2)				0.216** (0.089)	
Restarted (Τ3)				0.143 (0.087)	
Constant	0.095*	0.139**	0.119	0.026	
	(0.050)	(0.062)	(0.078)	(0.041)	
Adjusted R2	0.018	-0.001	0.037	0.020	
Observations	2178	726	726	726	
Notes: The table reports OLS regressions with dependent variable how many bags a household recycled during the respective period. Only households included that signed up in 2018 or later; only households that did not recycle during tlie baseline period. All regressions include a control for tlie liouse type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at. individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.091 for T1 = Τ2&Τ3: column (4) p=0.915 for Τ2 = T1, p=0.578 for Τ1 = Τ3, p=0.526 for Τ2 = T3. 0*, *, * indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.10.
E.		Full sample results
We conducted all analyses presented in this paper also witli the full sample to verify whether and how any findings differ. As in our main analysis, we start by looking at the treatment effects by period (see Tables E.1 and E.2). Again, we find that reminders significantly increase households’ recycling activity in period 2 among all treatment groups compared to the control group, and that this effect persists throughout the whole intervention period. In period 3, we can observe significant positive effects in the continuous treatment (but not in the interrupted ones). In period 4, we find significant positive effects in tlie continuous and the interrupted treatment (but not in the restarted group). Compared to results for households with a recent sign-up year, we can note that coefficients tend to be smaller and significance levels weaker (many results are now significant at the 10% level). The pattern persists when splitting up the analysis by baseline recycling activity (see Appendix E.4) or when looking at treatment effects on the intensive margin (see Appendix E.7 and E.8).
The same pattern holds when looking at the overall treatment effects over the whole intervention period. We find again that results are fairly similar to the ones presented for households with a more recent sign-up year (see Table E.8). Both the continuous and the interrupted treatments have a significant positive effect on households’ recycling activity over the whole intervention period, both regarding the number of periods a household recycled during the intervention period as well as whether a household recycled at all. Compared to the results presented for households that signed up more recently, we can note again that the coefficients for the full sample become slightly smaller.
The weaker effects that we observe among the full sample are not surprising as we now look: at a larger group of households among which many may have changed their phone numbers by now or moved away from the district given their early sign-up years. Table A.2 in Appendix A confirms that the percentage of households that recycled at all during the intervention period was higher among households witli a recent sign-up year than among those witli an older sign up year (< 2018), indicating that those recently signed-up households were more responsive to our intervention. We interpret these findings as support for our decision to focus our main analysis on those households that signed up more recently.

E.l. Full sample histograms of recycling frequency per period
Figure E.l: Histograms of recycling frequency during the baseline period (week 1-3),
comparing all treatment groups together witli the control group - full sample

Notes: The figure shows histograms for the recycling frequency during the baseline period (from zero to three times) in the control group and in the aggregated treatment groups, including the full sample. N per group = 348, the treatment groups together add up to Ν = 1,044.
Figure E.2: Histograms of recycling frequency during period 2 (week 4-6), comparing all
treatment groups together witli the control group - full sample

Control (TO)

All treatments (T1&T2&T3)

83.62

8-

80.27

5.17

7.18

4.02
3

Recycling frequency in period 2

9.39

5,75	4.60

"ο 1	2	3~

Notes: The figure shows histograms for the recycling frequency during period 2 (from zero to three times) in the control group and in the aggregated treatment groups, including the full sample. N per group = 348, the treatment groups together add up to Ν = 1,044.

Figure Ε.3: Histograms of recycling frequency during period 3 (week 7-9), comparing
the continuous and the interrupted treatment groups witlr tlie control group - full
sample

Recycling frequency in period 3

Notes: The figure shows histograms for the recycling frequency during period 3 (from zero to three times) in the control group and in the continuous and interrupted treatment groups, including the full sample. N per group = 348 (hence Ν = 696 for both interrupted groups together).
Figure E.4: Histograms of recycling frequency during period 4 (week 10-12), comparing
the continuous, interrupted and restarted treatment groups witlr tlie control group - full
sample

Recycling frequency in period 4

Notes: The figure shows histograms for the recycling frequency during period 4 (from zero to three times) in tlie control group and in the different treatment groups, including tlie full sample. N per group = 348.

E.2. Full sample graphs on weekly recycling behavior
Figure E.5: Percentages of households that recycled per week - full sample

week

— Control (TO) 	All treatments (Τ1&Τ2&Τ3)

(b) Pooling treatments witlr identical exposure

— Control (TO) 	All treatments (Τ1&Τ2&Τ3)
	Continuous (T1)		- ■ Interrupted (Τ2&Τ3)
	Interrupted (Τ2)	—	Restarted (Τ3)

Notes: The figure shows the percentages of households that recycled at least once per week in the control group and in the different treatment groups over the whole study period, focusing on the wliolc sample. Sub-figure E.5a conrpares all treatment groups pooled togetlrer witlr the control group; sub-figure E.5b pools treatment groups that have identical exposure as of caclr period in the horizontal axis. N(T0) = 348, N(T1&T2&T3) = 1,044, N(T1) = 348, N(T2&T3) = 698, N(T2) = 348, N(T3) = 348.

E.3. Full sample results: Treatment effects by period
Figure E.6: Proportion of households that recycled at least once per period - full sample

(a) All treatments vs. control

• Control (TO) · All treatments (T1&T2&T3)

(b) Pooling treatments witlr identical exposure

• Control (TO) · All treatments (Τ1&Τ2&Τ3) Continuous (Τ1)	· Interrupted & Restarted (Τ2&Τ3)
• Interrupted (Τ2)	· Restarted (Τ3)

(c) Each treatment separately

• Control (TO) · Continuous (Τ1)
• Interrupted (Τ2)	· Restarted (Τ3)

Notes: The figure shows the proportion of Irouseholds that recycled at least once per period in the control group and in the different treatment groups over the whole study period, focusing on the whole sample. Sub-figure E.6a compares all treatment groups pooled together witli the control group; sub-figure E.6b pools treatment groups that have identical exposure as of each period in the horizontal axis: and sub-figure E.6c compares the control group witli eacli treatment group separately. N(T0) = 348, N(T1&T2&T3) = 1,044, N(T1) = 348, N(T2&T3) = 698, N(T2) = 348, N(T3) = 348.

Table E.1: Treatment effects on whether households recycled at least once, by period -
full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.032**	0.037*			
	(0.016)	(0.020)			
Continuous (T1)			0.044*	0.040*	
			(0.025)	(0.023)	
Interrupted & Restarted (T2&T3)			0.014		
			(0.021)		
Interrupted (Τ2)				0.053**	
				(0.023)	
Restarted (Τ3)				0.013	
				(0.022)	
Constant	0.052*“	0.058"*	0.065***	0.031*	
	(0.016)	(0.020)	(0.020)	(0.017)	
Adjusted R2	0.325	0.332	0.331	0.312	
Observations	4176	1392	1392	1392	
Notes: The table reports OLS regressions with dependent variable equal to one if a household recycled at least once during the respective period. Full sample included. All regressions include a control for households’ binary baseline recycling activity and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.162 for T1 = T2&T3; column (4) p=0.583 for Τ2 = T1, p=0.250 for Τ1 = Τ3, p=0.088 for 12 = T3. ***, **, * indicate significance levels at 1, 5, and 10%, respectively. Panel regression analog is reported in Table F.11.
Table E.2: Treatment effects on whether households recycle at least once, by period -
full sample (logit)
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Τ1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.337**
(0.170)	0.372* (0.210)	0.433* (0.244) 0.157
(0.216)	0.448* (0.256)
0.581**
(0.251) 0.171
(0.254)	
Constant	-2.787*** (0.193)	-2.673*** (0.237)	-2.654“* (0.222)	-3.109*4*
(0.241)	
Pseudo R2	0.282	0.284	0.290	0.287	
Observations	4176	1392	1392	1392	
Notes: The table reports logistic regressions with dependent variable equal to one if a household recycled at least once during the respective period. Full sample included. All regressions include a control for households’ binary baseline recycling activity and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at individual household level in column (1). ' , ', indicate significance levels at 1, 5. and 10%, respectively. Panel regression analog is reported in Table F.12.

E.4. Full sample results: Heterogeneity by recycling at baseline
Table E.3: Treatment effects on whetlier liouseliolds recycled at least once, by period -
baseline recycling yes - full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Τ1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.106* (0.058)	0.154** (0.072)	0.167**
(0.083) 0.075
(0.074)	0.061 (0.089)
0.084 (0.086)
0.031 (0.089)	
Constant	0.635*** (0.070)	0.622*** (0.085)	0.688*** (0.082)	0.601*** (0.087)	
Adjusted R2	0.018	0.009	0.027	-0.007	
Observations	744	248	248	248	
Notes: The table reports OLS regressions	with dependent.	variable equal to one if?	a household	
recycled at least once during the respective period. Full sample included; only households that, recycled during the baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.198 for T1 = Τ2&Τ3; column (4) p=0.795 for Τ2 = Τ1, p=0.756 for Τ1 = Τ3, p=0.553 for Τ2 = Τ3. ***, **,* indicate significance levels at 1. 5, and 10%, respectively. Panel regression analog is reported in Table F.13.
Table E.4: Treatment effects on whetlier households recycled at least once, by period -
baseline recycling no - full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Τ1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.015 (0.014)	0.011 (0.018)	0.019 (0.024)
-0.002 (0.019)	0.036* (0.020)
0.045**
(0.021) 0.007
(0.018)	
Constant	0.056*** (0.015)	0.070*** (0.019)	0.067*** (0.018)	0.030** (0.015)	
Adjusted R2	0.012	0.003	0.026	0.011	
Observations	3432	1144	1144	1144	
Notes: The table reports OLS regressions	with dependent.	variable equal to one if?	a household	
recycled at least, once during the respective period. Full sample included; only households that, did not recycle during the baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.306 for T1 = Τ2&Τ3; column (4) p=0.710 for Τ2 - T1, p=0.161 for T1 - T3, p=0.078 for Τ2 - T3. ***, **, * indicate significance levels at 1. 5, and 10%, respectively. Panel regression analog is reported in Table F.14.
Table E.5: Treatment effects on recycling in period 2 and 3 combined - full sample
	Recycled p2 & p3 (1)	Recycled neither ρ2 nor p3
(2)	Recycled only ρ2 (3)	Recycled only p3 (4)	
Continuous (T1)	0.033	-0.0774*	0.022	0.022	
	(0.023)	(0.033)	(0.018)	(0.018)	
Interrupted & Restarted (Τ2&Τ3)	0.019	-0.039	0.018	0.002	
	(0.018)	(0.027)	(0.014)	(0.014)	
Predicted Probability Control (TO)	0.072***	0.843***	0.040***	0.040***	
	(0.015)	(0.022)	(0.011)	(0.012)	
Observations	1392	1392	1392	1392	

Notes: Marginal probabilities of a multinomial probit regressions on (1) whetlier households recycled at least once in both period 2 and period 3. (2) whether households recycled neither in period 2 nor in period 3, (3) whether households recycled only in period 2, (4) whether households recycled only in period 3. The regression includes a control for households’ binary baseline recycling activity and the house type, and use fixed effects for enumerators. Full sample included. Standard errors in parentheses. Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (1) ρ—0.492 for Τ1 — Τ2&Τ3; column (2) p=0.217 for T1 - T2&T3; column (3) ρ—0.822 for T1 — Τ2&Τ3; column (4) p=0.246 for T1 — T2&T3. "**, ", * indicate significance levels at. 1. 5, and 10%, respectively.
Table E.6: Treatment effects on recycling in period 2 and 3 combined - baseline
recycling yes - full sample
	Recycled ρ2 & ρ3 1(1)	Recycled neither p2 nor p3 (2)	Recycled only ρ2 (3)	Recycled only p3 (4)	
Continuous (Τ1)	0.151*	-0.148*	-0.019	0.016	
	(0.091)	(0.077)	(0.049)	(0.065)	
Interrupted & Restarted (Τ2&Τ3)	0.103	-0.140**	0.067	-0.031	
	(0.079)	(0.069)	(0.049)	(0.052)	
Predicted Probability Control (TO)	0.466*"	0.314***	0.085**	0.135***	
	(0.064)	(0.060)	(0.037)	(0.044)	
Observations	248	248	248	248	

Notes: Marginal probabilities of a multinomial probit regressions on (1) whether households recycled at least once in both period 2 and period 3. (2) whether households recycled neither in period 2 nor in period 3, (3) whether households recycled only in period 2, (4) whether households recycled only in period 3. The regression includes a control for the house type, and use fixed effects for enumerators. Full sample included. Only households included that recycled during the baseline period. Standard errors in parentheses. Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (1) ρ—0.544 for Τ1 — Τ2&Τ3; column (2) ρ—0.889 for Τ1 - T2&T3; column (3) ρ—0.060 for Τ1 — T2&T3; column (4) ρ—0.396 for Τ1 — Τ2&Τ3. ", * indicate significance levels at 1, 5, and 10%, respectively.
Table E.7: Treatment effects on recycling in period 2 and 3 combined — baseline
recycling no - full sample
	Recycled p2 & p3
(1)	Recycled neither p2 nor p3
(2)	Recycled only ρ2
(3)	Recycled only p3
(4)	
Continuous (Τ1)	0.007	-0.044	0.023	0.014	
	(0.017)	(0.027)	(0.017)	(0.015)	
Interrupted & Restarted (Τ2&Τ3)	-0.001	-0.007	0.006	-0.003	
	(0.014)	(0.021)	(0.013)	(0.012)	
Predicted Probability Control (TO)	0.041***	0.904**	0.028***	0.027***	
	(0.012)	(0.018)	(0.010)	(0.010)	
Observations	1144	1144	1144	1144	

Notes: Marginal probabilities of a multinomial probit regressions on (1) whether households recycled at least once in both period 2 and period 3, (2) whether households recycled neither in period 2 nor in period 3, (3) whether households recycled only in period 2, (4) whether households recycled only in period 3. The regression includes a control for the house type, and use fixed effects for enumerators. Full sample included. Only households included that did not recycle during the baseline period. Standard errors in parentheses. Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (1) p=0.576 for Τ1 - T2& T3; column (2) ρ—0.123 for Τ1 - T2&T3; column (3) ρ—0.242 for Τ1 - T2& T3; column (4) p—0.413 for Τ1 — Τ2&Τ3. ", * indicate significance levels at 1, 5, and 10%, respectively.

Figure E.7: Total recycling frequency during entire intervention period, by treatment -
full sample
(a) Pooled sample

Control (TO)

Continuous (Τ1)

Interrupted (T2

Restarted 13

Total recycling frequency during entire intervention period

Percent

(b) Baseline recycling yes

(c) Baseline recycling no

Control (TO)

Continuous (Τ1

Interrupted (12,

Restarted (13)

Total recycling frequency during entire intervention period

Total recycling frequency during entire intervention period

Notes: Tire figure shows histograms for the total recycling frequency during the entire intervention period (period 2-4). Concretely, it shows in how many of tire different periods of the intervention period households recycled at least once (from zero to three periods). Only households included with a recent sign-up year (> 2018). Sub-figure E.7a for pooled sample: Ν per group = 348; sub-figure E.7b for households that recycled during the baseline period: N(T0) = 63, N(T1) = 59, N(T2) = 65, N(T3) = 61; sub-figure E.7c for households that did not recycle during the baseline period: N(T0) = 285, N(T1) = 289, N(T2) = 283, N(T3) = 287.
Recycled in ...	no period
(1)	one period
(2)	two periods
(3)	three periods
(4)	
Panel A: Pooled sample (Ν = 1,392)
Continuous (Τ1)	-0.075”	0.029**	0.019**	0.027**	
	(0.033)	(0.013)	(0.009)	(0.012)	
Interrupted (Τ2)	-0.654**	0.025**	0.017**	0.023**	
	(0.033)	(0.013)	(0.009)	(0.012)	
Restarted (Τ3)	-0.010	0.004	0.003	0.003	
	(0.031)	(0.013)	(0.008)	(0.010)	
Predicted Probability Control (TO)	0.807***	0.106***	0.046***	A A ***
0.041	
	(0.022)	(0.012)	(0.007)	(0.008)	
Panel B: Recycled at baseline (Ν = 248)
Continuous (Τ1)	-0.085	-0.039	-0.005	0.130	
	(0.053)	(0.025)	(0.007)	(0.080)	
Interrupted (Τ2)	-0.086*	-0.040	-0.005	0.132*	
	(0.052)	(0.025)	(0.007)	(0.078)	
Restarted (Τ3)	-0.057	-0.023	-0.001	0.081	
	(0.056)	(0.023)	(0.004)	(0.080)	
Predicted Probability Control (TO)	0.222***	0.220***	0.171***	0.386***	
	(0.045)	(0.031)	(0.024)	(0.057)	
Panel C: No recycling at baseline (Ν = 1,144)
Continuous (Τ1)	-0.050*	0.022*	0.012*	0.016*	
	(0.028)	(0.013)	(0.007)	(0.009)	
Interrupted (Τ2)	-0.036	0.016	0.009	0.011	
	(0.028)	(0.013)	(0.007)	(0.009)	
Restarted (Τ3)	0.009	-0.004	-0.002	-0.002	
	(0.026)	(0.012)	(0.006)	(0.007)	
Predicted Probability Control (TO)	0.886***	0.065***	0.026***	0.023***	
	(0.019)	(0.010)	(0.006)	(0.006)	

Notes: Marginal probabilities of ordered probit regressions on (1) whether households did not recycle at all during the entire intervention period, (2) whether households recycled in one period of the intervention period, (3) whether households recycled in two periods of the intervention period, (4) whether households recycled in three periods of the intervention period. All regressions include a control for the house type, and use fixed effects for enumerators. The regressions for the pooled sample also include a control for households’ binary baseline recycling activity. Full sample included. Standard errors in parentheses. ***, ", * indicate significance levels at 1, 5. and 10%. respectively. Comparing the marginal probabilities of Τ1, Τ2 and Τ3, respectively, using a two-sided Wald test gives the following ρ-values:
Panel A: column (1) Τ1 = Τ2 p=0.788, Τ1 = Τ3 ρ=0.051, Τ2 = Τ3 p=0.095; column (2) Τ1 = Τ2 p=0.788, Τ1 = Τ3 p=0.054, Τ2 = Τ3 p=0.097; column (3) Τ1 = Τ2 p=0.788, Τ1 = Τ3 ρ=0.055, Τ2 = Τ3 p=0.099; column (4) Τ1 = Τ2 p=0.788, Τ1 = Τ3 p=0.056, Τ2 = Τ3 p=0.099;
Panel Β: column (1) Τ1 = Τ2 p=0.979, Τ1 = Τ3 p=0.561, Τ2 = Τ3 p=0.536; column (2) Τ1 = Τ2 p=0.979, Τ1 = Τ3 p=0.562, Τ2 = Τ3 p=0.534; column (3) Τ1 = Τ2 ρ=0.979, T1 = Τ3 p=0.581, Τ2 = Τ3 p=0.551: column (4) T1 = Τ2 p=0.979, Τ1 = T3 p=0.560, Τ2 = Τ3 p=0.534;
Panel C: column (1) T1 = Τ2 p=0.623, Τ1 = Τ3 p=0.033, Τ2 = Τ3 p=0.106; column (2) Τ1 = Τ2 ρ=0.623, T1 = Τ3 p=0.036, Τ2 = Τ3 p=0.109; column (3) Τ1 = Τ2 ρ=0.623, Τ1 = Τ3 ρ=0.041, Τ2 = Τ3 p=0.116; column (4) Τ1 = Τ2 p=0.623, Τ1 = Τ3 p=0.041, Τ2 = Τ3 p=0.116.
E.7. Full sample results: Intensive margin - recycling frequency per period
Table E.9: Treatment effects on how often households recycled per period - full sample
	Period 2-4
(1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.052*	0.030			
	(0.030)	(0.036)			
Continuous (Τ1)			0.088*	0.078*	
			(0.047)	(0.041)	
Interrupted & Restarted (T2&T3)			0.042 (0.040)		
Interrupted (Τ2)				0.100**
(0.041)	
Restarted (Τ3)				0.024 (0.039)	
Constant	0.073"	0.088**	0.100***	0.030	
	(0.030)	(0.037)	(0.037)	(0.031)	
Adjusted R2	0.430	0.481	0.417	0.396	
Observations	4176	1392	1392	1392	
Notes: The table reports OLS regressions with dependent variable how often a household recycled during the respective period (never up to three times). Full sample included. All regressions include a control for households’ baseline recycling activity (never up to Hirce times) and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p-0.255 for Τ1 = Τ2&Τ3; column (4) p-0.621 for Τ2 = T1, p-0.212 for Τ1 - Τ3, p-0.082 for Τ2 - T3. ***. "", * indicate significance levels at 1. 5, and 10%, respectively.
Table E.10: Treatment effects on how often households recycled per period - baseline
recycling yes - full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.178	0.138			
	(0.122)	(0.156)			
Continuous (Τ1)			0.315*	0.156	
			(0.173)	(0.178)	
Interrupted & Restarted (T2&T3)			0.210		
			(0.156)		
Interrupted (Τ2)				0.204	
				(0.173)	
Restarted (Τ3)				0.085	
				(0.186)	
Constant	0.125	0.084	0.273	0.026	
	(0.201)	(0.258)	(0.238)	(0.216)	
Adjusted R2	0.240	0.238	0.269	0.193	
Observations	744	248	248	248	
Notes: The table reports OLS regressions with dependent variable how often a household recycled during the respective period (never up to three times). Full sample included; only lionscholds that recycled during the baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) ρ-0.481 for Τ1 — T2&T3; column (4) p=0.791 for Τ2 - T1, p=0.707 for Τ1 - Τ3, p-0.529 for Τ2 - Τ3. ***, ' , indicate significance levels at 1. 5, and 10%, respectively.

Table Ε.11: Treatment effects on how often households recycled per period - baseline
recycling no - full sample
	Period 2-4 (0	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.025	0.007			
	(0.023)	(0.027)			
Continuous (Tl)			0.045	0.064”	
			(0.041)	(0.032)	
Interrupted & Restarted (T2&T3)			0.003 (0.033)		
Interrupted (Τ2)				0.077"
(0.033)	
Restarted (Τ3)				0.013 (0.027)	
Constant	0.077”	0.101"’	0.094”’	0.036	
	(0.024)	(0.028)	(0.031)	(0.023)	
Adjusted R2	0.009	0.000	0.016	0.010	
Observations	3432	1144	1144	1144	
Notes: The table reports OLS regressions with dependent, variable how often a household recycled during tlie respective period (never up to three times). Full sample included: only households that did not recycle during the baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at individual household level in column (1). Comparing treatment, coefficients using two-sided Wald tests gives following p-values: column (3) p—0.268 for Τ1 = Τ2&Τ3; column (4) p-0.741 for Τ2 - Th p-0.133 for Τ1 - Τ3, p-0.070 for Τ2 - Τ3.
' , indicate significance levels at 1, 5, and 10%, respectively.
E.8. Full sample results: Intensive margin - number of bags recycled per period
Table E.12: Treatment effects on the number of bags recycled by households per period
- full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)	0.050	0.049			
	(0.103)	(0.129)			
Continuous (Τ1)			0.108	0.079	
			(0.151)	(0.132)	
Interrupted & Restarted (T2&T3)			-0.041		
			(0.137)		
Interrupted (Τ2)				0.161	
				(0.140)	
Restarted (Τ3)				0.037	
				(0.141)	
Constant	0.309*	0.289*	0.435*"	0.200*	
	(0.125)	(0.171)	(0.139)	(0.121)	
Adjusted R2	0.442	0.470	0.446	0.407	
Observations	4176	1392	1392	1392	
Notes: The table reports OLS regressions with dependent variable how many bags a household recycled during the respective period. Full sample included. All regressions include a control for households’ baseline recycling activity (mean of recycled bags) and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.215 for Τ1 = T2&T3; column (4) p-0.554 for Τ2 = T1, p-0.765 for Τ1 = Τ3, p=0.399 for Τ2 = Τ3. **, "*, * indicate significance levels at 1, 5, and 10%, respectively.
Table E.13: Treatment effects on the number of bags recycled by households per period
- baseline recycling yes - full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Τ1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	-0.070
(0.514)	-0.013
(0.688)	0.147 (0.676)
-0.300 (0.653)	-0.198 (0.662)
0.204 (0.681)
-0.156 (0.723)	
Constant	1.600	1.426	2.158*	1.243	
	(1.023)	(1.512)	(1.100)	(0.974)	
Adjusted R2	0.316	0.320	0.357	0.242	
Observations	744	248	248	248	
Notes: Tlie table reports OLS regressions with dependent variable how many bags a household recycled during tlie respective period. Full sample included; only households that recycled during the baseline period. All regressions include a control for households’ baseline recycling activity (mean of recycled bags) and the house type, and use fixed effects for enumerators. Robust standard errors in parentheses; standard errors clustered at individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values; column (3) p-0.379 for Τ1 = T2&T3; column (4) p-0.547 for Τ2 - T1, p-0.951 for Τ3 — Τ1, p=0.622 for Τ2 — Τ3. **, ", * indicate significance levels at 1, 5, and 10%, respectively.

Table Ε.14: Treatment effects on the number of bags recycled by households per period 11
- baseline recycling no - full sample
	Period 2-4 (1)	Period 2 (2)	Period 3 (3)	Period 4 (4)	
All treatments (T1&T2&T3)
Continuous (Τ1)
Interrupted & Restarted (T2&T3)
Interrupted (Τ2)
Restarted (Τ3)	0.076 (0.053)	0.070 (0.056)	0.123 (0.107)
-0.004
(0.081)	0.149* (0.078)
0.143*
(0.078) 0.066
(0.074)	
Constant	0.196*" (0.057)	0.195*** (0.057)	0.271*" (0.079)	0.119* (0.068)	
Adjusted R2	0.008	0.000	0.014	0.007	
Observations	3432	1144	1144	1144	
Notes: The table reports OLS regressions with dependent	variable how	many bags &	i household	
recycled during the respective period. Full sample included; only households that did not recycle during tlie baseline period. All regressions include a control for the house type, and use fixed effects for enumerators. Robust standard errors in parentheses: standard errors clustered at. individual household level in column (1). Comparing treatment coefficients using two-sided Wald tests gives following p-values: column (3) p=0.196 for Τ1 — T2&T3; column (4) p=0.947 for Τ1 = Τ2, ρ=0.339 for Τ1 = Τ3, p=0.375 for Τ2 = T3. **, "*, * indicate significance levels at 1. 5, and 10%, respectively.
F.		Panel regression analyses
We estimate a set of random-effects (RE) panel regressions using tire following specification:
3	4	3 4
Y = a +SB, Tg +Z& P +SZgt (Tg P) +X0+u;+e	(2) g=1	t=2	g=1 t=2
with Yu being a binary variable equal to one if household i recycled at least once in period t, zero otherwise. Tig is a set of indicator variables for the treatment groups, using the control group as reference. Pt includes period fixed effects, with period 1 as the reference. Tig · Pt are interaction terms capturing the effect of each treatment group in each post-treatment period. The vector X includes controls for households’ baseline recycling activity, the house type, and indicator variables for tlie different enumerators, ι^ is an unobserved, time-invariant householdspecific random effect (random intercept) and €it is an idiosyncratic error that varies across households and periods.
We begin by reporting Table F.1, which presents the direct results from our random-effects (RE) panel specification. As in our primary analysis, the sample is restricted to households that enrolled in 2018 or later. Coefficients on the treatment—by—period interactions capture the effect of each experimental arm (Τ1, Τ2, Τ3) relative to the control within each post-treatment period. To facilitate comparison with the sequence of results in the main analysis, Table F.2 then summarizes these RE estimates in a similar layout as Tables 2 and 3 and the complementary OLS and logit specifications in Appendices D and E. In Table F.2 and subsequent tables, Panel (1) above the horizontal line reports the treatment—by-period interaction coefficients read directly from the RE regression, while below the horizontal line pooled entries (combined arms and the control row) are obtained via Wald tests; Panel (2) reports average effects across periods 2-4. computed as simple means of the corresponding interaction coefficients, with pooled averages weighted by arm-specific sample sizes in the sample.

Table F.1: Random-effects panel regression with treatment-by-period interactions
	Coef.	SE	
Period effects (baseline: Period 1)
Period 2	-0.0324	(0.0274)	
Period 3	-0.0185	(0.0237)	
Period 4	-0.0509**	(0.0220)	
Treatments (baseline: Control)			
Continuous (Τ1)	-0.0051	(0.0117)	
Interrupted (Τ2)	0.0056	(0.0118)	
Restarted (Τ3)	-0.0008	(0.0120)	
Interactions: Treatment x Period			
Continuous x Period 2	0.0735**	(0.0373)	
Continuous x Period 3	0.0870***	(0.0332)	
Continuous χ Period 4	0.0509	(0.0334)	
Interrupted x Period 2	0.0451	(0.0357)	
Interrupted x Period 3	0.0439	(0.0337)	
Interrupted x Period 4	0.0425	(0.0326)	
Restarted x Period 2	0.0456	(0.0346)	
Restarted x Period 3	0.0141	(0.0330)	
Restarted x Period 4	0.0201	(0.0324)	
Other covariates			
Baseline recycler (=1)	0.6847***	(0.0224)	
House	0.0515***	(0.0169)	
Constant	0.0476***	(0.0121)	
Observations	3,592		
Households (groups)	898		
Notes: Random-effects GLS: robust standard errors clustered at the household level. Dependent variable equals 1 if a household recycled at least once in the respective period; period 1 is the baseline. Treatment indicators are relative to the control arm; enumerator indicators included but not reported. Only households that signed up in 2018 or later are included., . indicate significance levels at 1. 5, and 10%, respectively.
	(1)	(2)	
	Period 1	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	-0.005	0.074**	0.087***	0.051	0.070*	
	(0.012)	(0.037)	(0.033)	(0.033)	(0.029)	
Interrupted (Τ2)	0.006	0.04.5	0.044	0.042	0.044	
	(0.012)	(0.036)	(0.034)	(0.033)	(0.029)	
Restarted (Τ3)	-0.001	0.046	0.014	0.020	0.027	
	(0.012)	(0.035)	(0.033)	(0.032)	(0.028)	
All treatments (T1&T2&T3)	0.000	0.054*	0.048*	0.038	0.047’	
	(0.010)	(0.030)	(0.027)	(0.026)	(0.024)	
Interrupted & Restarted (Τ2&Τ3)	0.002	0.045	0.029	0.031	0.035	
	(0.010)	(0.032)	(0.029)	(0.028)	(0.025)	
Predicted Probability Control (T0)	0.194"*	0.162***	0.176***	0.144**	0.160’**	
	(0.008)	(0.024)	(0.021)	(0.019)	(0.012)	
Overall R2			0.487			
Intraclass correlation			0.265			
Observat ione			3592			

tlie corresponding *** ** *. ..
, , indicate

Notes: The table reports a random effects panel regression where tlie dependent variable equals one if a household recycled at least once during the respective period. Tire regression includes controls for households’ binary baseline recycling activity, house type, and enumerator fixed effects. Only households that signed up in 2018 or later are included. In Panel (1) and above tire horizontal line, we report, tlie main coefficients from a random-effects panel regression with treatment-by-period interactions and the prespecified controls: the Τ1, Τ2, and Τ3 rows arc the interaction coefficients read directly from the regression. Tlie remaining entries in that panel (below tlie horizontal line: pooled arms and tlie control row) are obtained with Wald tests. Panel (2) reports average effects over periods 2-4: for each arm this is tlie simple mean of tlie three period-specific interaction coefficients. When pooling arms (T2&T3 or All treatments), coefficients are combined using sample-size weights from the subsample. Standard errors in parentheses are cluster-robust at the household level: for post-estimation entries they reflect, tlie delta method from linear combinations. Two-sided tests. Only households that signed up in 2018 or later arc included, significance levels at 1, 5, and 10%, respectively.
Table F.3: Treatment effects on whether households recycled at least once, by period -
baseline recycling yes vs. no (panel regression version of Table 3)
		(1) 	(2)
Period 2	Period 3	Period 4	Period 2-4
BR = yes BR = no BR = yes BR = no BR = yes BR = no BR = yes BR = no	
Continuous (T1)	0.211**	0.030	0.199”	0.053’	0.010	0.048’	0.140’	0.044*
(0.107)	(0.031)	(0.095)	(0.030)	(0.110)	(0.025)	(0.084)	(0.023)	
Interrupted (T2)	0.229*6	0.005	0.086	0.038	0.051	0.045’	0.122	0.029
(0.101)	(0.029)	(0.098)	(0.029)	(0.103)	(0.024)	(0.083)	(0.022)	
Restarted (T3)	0.273***	-0.009	0.039	0.008	-0.004	0.026	0.102	0.008
(0.100)	(0.028)	(0.103)	(0.027)	(0.107)	(0.022)	(0.083)	(0.021)	
All treatments (T1&T2&T3)	0.237“*	0.008	0.107	0.033	0.019	0.040’	0.121*	0.027
(0.100)	(0.024)	(0.083)	(0.022)	(0.087)	(0.018)	(0.070)	(0.017)	
Interrupted & Restarted (T2&T3)	0.251“*	-0.002	0.063	0.023	0.024	0.036’	0.112	0.019
(0.090)	(0.025)	(0.088)	(0.024)	(0.092)	(0.019)	(0.074)	(0.018)	
Predicted Probability Control (TO)	0.490***	0.083“*	0.633”'	0.066*’*	0.585*	0.037*"	0.569**	0.062*”
(0.078)	(0.021)	(0.074)	(0.018)	(0.076)	(0.014)	(0.063)	(0.014)	
Overall R2 Observations	0.523 3592	
Notes: BR = baseline recycling. Tlie table reports a random effects panel regression witli dependent variable equal to one if a household recycled at least once during tlie respective period. Coefficients in column (1) arc from tlie panel regression: column (2) is estimated via post-estimation Wald tests. The regression includes a control for households’ binary baseline recycling activity, house type, and enumerator fixed effects. Only households that signed up in 2018 or later arc included. Robust standard errors in parentheses; standard errors clustered at the household level. ' , , indicate significance levels at 1, 5, and 10%, respectively.

	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (Τ1)	1.313*	1.460***	0.984	1.252**	
	(0.671)	(0.563)	(0.636)	(0.530)	
Interrupted (Τ2)	0.822	0.762	0.834	0.806	
	(0.646)	(0.586)	(0.600)	(0.520)	
Restarted (Τ3)	0.840	0.256	0.389	0.495	
	(0.638)	(0.604)	(0.625)	(0.524)	
All treatments (T1&T2&T3)	0.986*	0.818*	0.734	0.846’	
	(0.566)	(0.490)	(0.498)	(0.440)	
Interrupted & Restarted (Τ2&Τ3)	0.831	0.514	0.616	0.654	
	(0..583)	(0.520)	(0.526)	(0.460)	
Predicted Probability Control (TO)	0.162***	0.175***	0.145***	0.161***	
	(0.022)	(0.019)	(0.017)	(0.011)	
Log pseudolikelihood Intraclass correlation Observations		-915.481
0.560
3592		
Notes: The table reports a random-effects panel logit regression with dependent variable equal to one if a household recycled at least once during tlie respective period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later. Tlie regression includes a control for households’ baseline recycling activity, house type, and enumerator fixed effects. Robust standard errors in parentheses; standard errors clustered at tlie household level. * , *, ' indicate significance levels at 1, 5, and 10%, respectively.

Table F.5: Treatment effects on how often households recycled per period (panel
regression version of Table D.3)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (Τ1)	0.096	0.151**	0.101*	0.116**	
	(0.059)	(0.061)	(0.054)	(0.049)	
Interrupted (Τ2)	0.059	0.076	0.078	0.071	
	(0.059)	(0.060)	(0.054)	(0.049)	
Restarted (Τ3)	0.022	0.048	0.039	0.036	
	(0.060)	(0.060)	(0.058)	(0.051)	
All treatments (T1VT2&T3)	0.058	0.091*	0.072*	0.074*	
	(0.050)	(0.050)	(0.043)	(0.041)	
Interrupted & Restarted (Τ2&Τ3)	0.041	0.062	0.059	0.054	
	(0.053)	(0.052)	(0.047)	(0.044)	
Predicted Probability Control (TO)	0.315***	0.315***	0.241’**	0.290***	
	(0.042)	(0.040)	(0.031)	(0.022)	
Overall R1		0.562			
Intraclass correlation		0.335			
Observations		3592			
Notes: Tlie table reports a random effects panel regression with dependent variable liow often a household recycled per period (never up to three times). Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later. The regression includes a control for households’ baseline recycling activity (never up to three times), house type, and enumerator fixed effects. Robust standard errors in parentheses; standard errors clustered at, tlie household level. * , *, ' indicate significance levels at 1, 5, and 10%, respectively.

	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (Τ1)	0.273	0.357	0.129	0.253	
	(0.239)	(0.230)	(0.219)	(0.189)	
Interrupted (Τ2)	0.280	0.149	0.086	0.172	
	(0.238)	(0.226)	(0.203)	(0.189)	
Restarted (Τ3)	0.132	0.175	0.001	0.103	
	(0.250)	(0.242)	(0.242)	(0.210)	
All treatments (T1&T2&T3)	0.228	0.219	0.070	0.172	
	(0.208)	(0.198)	(0.177)	(0.166)	
Interrupted & Restarted (Τ2&Τ3)	0.209	0.161	0.046	0.139	
	(0.217)	(0.208)	(0.190)	(0.176)	
Predicted Probability Control (TO)	1.190’'’	1.238’”	1.071’”	1.167”*	
	(0.178)	(0.163)	(0.138)	(0.093)	
Overall R2		0.346			
Intraclass correlation		0.322			
Observations		688			
Notes: The table reports a random effects panel regression with dependent variable liow often a household recycled per period (never up to three times). Coefficients in column (1) are from tlie panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later; only households that, recycled during the baseline period. The regression includes a control for households’ baseline recycling activity (never up to three times), house type, and enumerator fixed abust standard errors in parentheses: standard errors clustered at the household level. , , significance levels at 1, 5, and 10%, respectively.

effects.

Table F.7: Treatment effects on how often households recycled per period - baseline
recycling no (panel regression version of Table D.5)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (Τ1)	0.046	0.096"	0.081”	0.074*	
	(0.045)	(0.052)	(0.037)	(0.038)	
Interrupted (Τ2)	0.008	0.062	0.082”	0.051	
	(0.041)	(0.048)	(0.037)	(0.035)	
Restarted (Τ3)	-0.005	0.017	0.047	0.020	
	(0.040)	(0.044)	(0.033)	(0.033)	
All treatments (T1&T2&T3)	0.016	0.058	0.070”"	0.048’	
	(0.033)	(0.037)	(0.025)	(0.027)	
Interrupted & Restarted (Τ2&Τ3)	0.002	0.040	0.065”	0.036	
	(0.035)	(0.039)	(0.028)	(0.028)	
Predicted Probability Control (TO)	0.103"”	0.092”’	0.040”	0.079”*	
	(0.028)	(0.029)	(0.017)	(0.015)	
Overall R2		0.041			
Intraclass correlation		0.385			
Observations		2904			
Notes: Tlie table reports a random effects panel regression with dependent variable liow often a household recycled per period (never up to three times). Coefficients in column (1) are from tlie panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later: only households that did not recycle during the baseline period. The regression includes a control for tlie house type, and enumerator fixed effects. Robust standard errors in parentheses: standard errors clustered at. the household level. * \ h indicate significance levels at 1. 5, and 10%, respectively.
Table F.8: Treatment effects on tlie number of bags recycled by liouseliolds per period
(panel regression version of Table D.6)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (Τ1)	0.172	0.170	-0.010	0.111	
	(0.165)	(0.187)	(0.153)	(0.143)	
Interrupted (Τ2)	0.024	0.008	-0.006	0.009	
	(0.163)	(0.194)	(0.169)	(0.153)	
Restarted (Τ3)	-0.067	-0.175	-0.004	-0.082	
	(0.173)	(0.190)	(0.194)	(0.159)	
All treatments (T1&T2&T3)	0.041	-0.001	-0.007	0.011	
	(0.130)	(0.156)	(0.132)	(0.120)	
Interrupted & Restarted (T2&T3)	-0.021	-0.082	-0.005	-0.036	
	(0.141)	(0.166)	(0.148)	(0.131)	
Predicted Probability Control (T0)	0.782***	0.917”*	0.741**1	0.813*"	
	(0.108)	(0.137)	(0.107)	(0.068)	
Overall R2		0.557			
Intraclass correlation		0.383			
Observations		3592			
Notes: The table reports a random effects panel regression with dependent variable liow many bags a household recycled per period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later. The regression includes a control for households’ baseline recycling activity (mean of recycled bags), house type, and enumerator fixed effects. Robust standard errors in parentheses: standard errors clustered at the household level. '. , indicate significance levels at 1, 5, and 10%, respectively.

Table F.9: Treatment effects on the number of bags recycled by households per period -
baseline recycling yes (panel regression version of Table D.7)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	-0.091	-0.249	-0.990	-0.444	
	(0.688)	(0.802)	(0.742)	(0.627)	
Interrupted (Τ2)	0.161	-0.360	-0.824	-0.341	
	(0.780)	(0.879)	(0.767)	(0.712)	
Restarted (Τ3)	-0.676	-0.972	-0.663	-0.771	
	(0.785)	(0.871)	(0.935)	(0.745)	
All treatments (T1&T2&T3)	-0.196	-0.535	-0.818	-0.516	
	(0.609)	(0.717)	(0.646)	(0.571)	
Interrupted & Restarted (T2&T3)	-0.240	-0.653	-0.747	-0.547	
	(0.663)	(0.765)	(0.709)	(0.621)	
Predicted Probability Control (TO)	3.310***	3.810”*	3.524*”	3.548***	
	(0.512)	(0.614)	(0.529)	(0.319)	
Overall R2		0.425			
Intraclass correlation		0.383			
Observations		688			
Notes: The table reports a random effects panel regression with dependent variable liow many bags a household recycled per period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later; only households that recycled during the baseline period. Tlie regression includes a control for households’ baseline recycling activity (mean of recycled bags), house type, and enumerator fixed effects. Robust standard errors in parentheses: standard errors clustered at tlie household level. , , indicate significance levels at 1, 5, and 10%, respectively.

Table F.10: Treatment effects on the number of bags recycled by households per period
- baseline recycling no (panel regression version of Table D.8)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	0.220*	0.262*	0.196**	0.226**	
	(0.128)	(0.139)	(0.080)	(0.099)	
Interrupted (T2)	-0.008	0.101	0.202**	0.099	
	(0.069)	(0.110)	(0.089)	(0.075)	
Restarted (Τ3)	0.079	0.017	0.155*	0.084	
	(0.100)	(0.109)	(0.088)	(0.082)	
All treatments (T1&T2&T3)	0.096	0.126	0.185***	0.135**	
	(0.071)	(0.092)	(0.055)	(0.060)	
Interrupted & Restarted (T2&T3)	0.035	0.059	0.179***	0.091	
	(0.070)	(0.094)	(0.066)	(0.063)	
Predicted Probability Control (T0)	0.172***	0.218***	0.069**	0.153”*	
	(0.048)	(0.071)	(0.030)	(0.030)	
Overall R2		0.036			
Intraclass correlation		0.370			
Observations		2904			
Notes: The table reports a random effects panel regression with dependent variable liow many bags a household recycled per period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Only households included that signed up in 2018 or later; only households that did not recycle during the baseline period. The regression includes a control for the house type, and enumerator fixed effects. Robust standard errors in parentheses: standard errors clustered at the household level. ,, indicate significance levels at 1, 5, and 10%, respectively.

Table F.11: Treatment effects on whether households recycled at least once, by period -
full sample (panel regression version of Table E.1)
		(1) 	(2)
Period 2	Period 3	Period 4 Periods 2-4	
Continuous (T1)	0.049*	0.046*	0.043	0.046*
(0.029)	(0.028)	(0.027)	(0.024)	
Interrupted (Τ2)	0.034	0.029	0.049*	0.037
(0.028)	(0.028)	(0.027)	(0.024)	
Restarted (Τ3)	0.029	-0.009	0.014	0.011
(0.027)	(0.027)	(0.026)	(0.023)	
All treatments (T1&T2&T3)	0.037	0.022	0.035*	0.032
(0.023)	(0.023)	(0.021)	(0.020)	
Interrupted & Restarted (T2&T3)	0.032	0.010	0.032	0.024
(0.024)	(0.024)	(0.023)	(0.021)	
Predicted Probability Control (TO)	0.164***	0.175***	0.138***	0.159***
(0.018)	(0.018)	(0.016)	(0.010)	
Overall R2
Intraclass correlation
Observations	0.460
0.287 5568	
Notes: The table reports a random effects panel regression witli dependent variable equal to one if a household recycled at least once during tlie respective period. Coefficients in column (1) arc from tlie panel regression; column (2) is estimated via. post-estimation Wald tests. Full sample included. Tlie regression includes a control for households’ binary baseline recycling activity, house type, and enumerator fixed effects. Robust standard errors in parentheses; standard errors clustered at. the household level.
, ' . indicate significance levels at. 1, 5, and 10%, respectively.

Table F.12: Treatment effects on whether households recycle at least once, by period -
full sample (panel logit regression version of Table E.2)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	0.867*	0.792	0.836	0.832*	
	(0.510)	(0.484)	(0.510)	(0.432)	
Interrupted (T2)	0.618	0.501	0.938*	0.686	
	(0.495)	(0.500)	(0.503)	(0.433)	
Restarted (Τ3)	0.536	-0.186	0.240	0.197	
	(0.497)	(0.515)	(0.519)	(0.436)	
All treatments (T1&T2&T3)	0.674	0.369	0.671	0.571	
	(0.422)	(0.416)	(0.414)	(0.360)	
Interrupted & Restarted (T2&T3)	0.577	0.158	0.589	0.441	
	(0.440)	(0.442)	(0.440)	(0.380)	
Predicted Probability Control (T0)	0.163"*	0.173***	0.139***	0.158***	
	(0.017)	(0.017)	(0.014)	(0.009)	
Log pseudolikelihood Intraclass correlation Observations		-1403.081 0.585 5568		
Notes: The table reports a random-effects panel logit regression with dependent variable equal to one if a household recycled at least once during tlie respective period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Full sample included. The regression includes a control for households’ binary baseline recycling activity, house type, and enumerator fixed effects. Robust standard errors in parentheses; standard errors clustered at the household level.
, ' , indicate significance levels at 1, 5, and 10%, respectively.

Table F.13: Treatment effects on whether households recycled at least once, by period -
baseline recycling yes - full sample (panel regression version of Table Ε.3)
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	0.122	0.158*	0.055	0.112	
	(0.088)	(0.085)	(0.090)	(0.072)	
Interrupted (T2)	0.168**	0.105	0.091	0.121*	
	(0.085)	(0.085)	(0.087)	(0.070)	
Restarted (Τ3)	0.182*	0.052	0.035	0.090	
	(0.085)	(0.088)	(0.090)	(0.071)	
All treatments (T1&T2&T3)	0.158**	0.105	0.061	0.108’	
	(0.072)	(0.071)	(0.073)	(0.059)	
Interrupted & Restarted (Τ2&Τ3)	0.175**	0.079	0.063	0.106*	
	(0.075)	(0.076)	(0.077)	(0.062)	
Predicted Probability Control (TO)	0.556***	0.587***	0.556***	0.566*1	
	(0.063)	(0.061)	(0.061)	(0.036)	
Overall R2		0.147			
Intraclass correlation		0.317			
Observations		992			
Notes: The table reports a random effects panel regression with dependent variable equal to one if a household recycled at least, once during the respective period. Coefficients in column (1) are from the panel regression; column (2) is estimated via post-estimation Wald tests. Full sample included; only households that recycled during the baseline period. The regression includes a control for households’ binary baseline recycling activity, house type, and enumerator fixed effects. Robust standard errors in parentheses; standard errors clustered at tlie household level. , , indicate significance levels at 1, 5. and 10%, respectively.
	(1)	(2)	
	Period 2	Period 3	Period 4	Periods 2-4	
Continuous (T1)	0.027	0.016	0.034*	0.026	
	(0.024)	(0.024)	(0.020)	(0.019)	
Interrupted (T2)	0.00S	0.015	0.043”	0.022	
	(0.023)	(0.024)	(0.021)	(0.019)	
Restarted (Τ3)	-0.008	-0.025	0.007	-0.009	
	(0.022)	(0.022)	(0.018)	(0.017)	
All treatments (T1&T2&T3)	0.009	0.002	0.028*	0.013	
	(0.019)	(0.019)	(0.015)	(0.015)	
Interrupted & Restarted (T2&T3)	-0.000	-0.005	0.025	0.006	
	(0.019)	(0.020)	(0.016)	(0.015)	
Predicted Probability Control (T0)	0.077*”	0.084*”	0.046**1	0.069”*	
	(0.016)	(0.016)	(0.012)	(0.009)	
Overall R2		0.035			
Intraclass correlation		0.334			
Observations		4576			
Notes: The table reports a random effects panel regression with dependent variable equal to one if a household recycled at least once during the respective period. Coefficients in column (1) are from tlie panel regression: column (2) is estimated via post-estimation Wald tests. Full sample included; only households that did not recycle during the baseline period. Tlie regression includes a control for the house type, and enumerator fixed effects. Robust standard errors in parentheses: standard errors clustered at the household level. ,, indicate significance levels at 1, 5. and 10%, respectively.