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(Ineffective) Messages to Encourage Recycling: Evidence from a Randomized Evaluation in Peru
Initial registration date
May 18, 2016
May 18, 2016 3:34 PM EDT
Other Primary Investigator(s)
School of International Development and Global Studies and Department of Economics, University of Ottawa
GiveDirectly (current); Yale University (former)
Dartmouth College and Innovations for Poverty Action
Additional Trial Information
There is growing interest in using messaging to drive pro-social behaviors, which contribute to investment in public goods. We worked with a leading NGO in Peru to randomize nine different pro-recycling messages that were crafted based on best practice, prior evidence, and theories of behavioral change. Different variants emphasized information on environmental or social benefits, social comparisons, social sanctions, authority, and/or reminders. None of the messages had significant effects on recycling behavior. However, reducing the cost of ongoing participation--by providing a recycling bin--significantly increased recycling among enrolled households.
Chong, Alberto et al. 2016. "(Ineffective) Messages to Encourage Recycling: Evidence from a Randomized Evaluation in Peru." AEA RCT Registry. May 18.
Randomized 9 different recycling enrollment messages that were crafted based on best practice, prior evidence, and theories of behavioral change. The control group received PRISMA's (leading Peruvian NGO) standard marketing: door-to-door canvassing. The treatment groups, randomized at the household level, received this in addition to a flier introducing the recycling program and a "treatment message" via text messages. We tested four main information campaigns:
i) a focus on social norms, encouraging recipients to "conform" to the pro-environmental behavior of their peers; ii) a focus on social sanctions, informing individuals that the participation rates of their street would be shared with others within and outside their community; iii) an injunctive to recycle that was endorsed by religious or government authorities; iv) a purely informational campaign with messages which stressed the social or environmental benefits of recycling and urged individuals to participate. The relative effectiveness of these 9 treatments was then compared with a separate evaluation of 3 randomly assigned treatments meant to ease economic barriers to increase participation intensity in a sample of participants in the recycling program. One provided a free recycling bin, and a second a bin with a sticker containing instructions on how to sort recyclables from non-recyclables (i.e., information on the logistics of recycling). These were compared to a control group which received nothing. A separate treatment, randomized within the same group, were sent weekly SMS reminders the day before recyclables would be picked up from the curb.
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
participates at any time, participation ratio, participates during either of last 2 visits
Primary Outcomes (explanation)
- "Participates at any time" is an indicator equal to 1 if the family participated in the program and gave at least once.
- "Participation ratio" is the ratio of the number of times a household turned in residuals over the number of opportunities it had to turn in residuals. This variable measures the strength of commitment to the program. In constructing this measure, the denominator, opportunities to turn in residuals, includes instances in which there was nobody at the household when the residual collector visited. - "Participates during either of last 2 visits" is an indicator of whether the household turned in residuals during one of the last two canvassing weeks (weeks [n] and [N] of the marketing/enrollment campaign). It measures the initial persistence of households’ commitment to the program.
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Working with PRISMA, we designed a two-part study to help expand their recycling program. The first part of the experiment tested different messaging treatments designed to increase enrollment in the door-to-door recycling program (the "participation" study), and the second tested different methods of increasing recycling compliance for those who participated in the program (the "participation intensity" study).
Experimental Design Details
in office by a computer (household level randomization stratifying on streets and cellphone ownership)
stratified, household-level randomization
Was the treatment clustered?
Sample size: planned number of clusters
6,718 households for the participation study and 1,785 households for the participation intensity study
Sample size: planned number of observations
Take up Sample: 6,718 households in new areas; Participation Sample: 1,785 households already registered in the program
Sample size (or number of clusters) by treatment arms
Take up Sample: 6,718 households in new areas.
Flyer treatments (10 cells): "Conformity wealthy", "Conformity poor", “Signaling wealthy”, “Signaling poor”, "Authority Religious", "Authority Municipal", "Environmental emphasis" and "Social emphasis" account for 8.75 percent of the sample each, while the "Signaling proximate" treatment was assigned to 12.5 percent. Control was 17.5 percent. SMS owners represented 35% of sample and received additional reinforcements. Participation Sample: 1,785 households already registered in the program of which 829 provided cellphone number.
SMS treatment (3 cells among 829 with cellphone): "Generic SMS", "Personalized SMS," and no SMS. Bin treatment (3 cells among all 1,785 households): 303 bin to store their recyclables, 301 a plastic bin with a sticker, or 1182 no bin.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
INSTITUTIONAL REVIEW BOARDS (IRBs)
Innovations for Poverty Action IRB-USA
IRB Approval Date
IRB Approval Number
Post Trial Information
Is the intervention completed?
Intervention Completion Date
August 31, 2010, 12:00 AM +00:00
Is data collection complete?
Data Collection Completion Date
August 31, 2010, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Participation Study: 5,250 households
Participation Intensity Study: 1,785 households
Total: 7035 households
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
We tested for differential attrition rates between treatment groups and found no significant differences. Our final sample for the participation study comprised 5,250 households.
Final Sample Size (or Number of Clusters) by Treatment Arms
Reports, Papers & Other Materials
There is growing interest in using messaging to drive prosocial behaviors, which contribute to investment in public goods. The authors worked with a leading nongovernmental organization in Peru to randomize nine different prorecycling messages that were crafted on the basis of best practices, prior evidence, and theories of behavioral change. Different variants emphasized information on environmental or social benefits, social comparisons, social sanctions, authority, and reminders. None of the messages had significant effects on recycling behavior. However, reducing the cost of ongoing participation by providing a recycling bin significantly increased recycling among enrolled households.
Chong, Alberto, Dean Karlan, Jeremy Shapiro, Jonathan Zinman. "(Ineffective) Messages to Encourage Recycling: Evidence from a Randomized Evaluation in Peru," The World Bank Policy Research Working Paper 6548, July 2013.
REPORTS & OTHER MATERIALS