Can children’s engagement in recycling processes reduce household waste?

Last registered on October 23, 2023

Pre-Trial

Trial Information

General Information

Title
Can children’s engagement in recycling processes reduce household waste?
RCT ID
AEARCTR-0003300
Initial registration date
May 15, 2019

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
May 20, 2019, 2:24 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
October 23, 2023, 3:47 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Primary Investigator

Affiliation
University of Gothenburg

Other Primary Investigator(s)

PI Affiliation
University of Southern Denmark
PI Affiliation
University of Gothenburg

Additional Trial Information

Status
Completed
Start date
2018-08-01
End date
2019-12-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We run a randomized controlled trial with school children aged 10-16 in Falkenberg and Varberg municipality, Sweden. Roughly 400-500 students across at least 33 school classes are expected to participate in the study. Randomization occurs within classes. Both treated and control students are visited by the experimenters and given an exercise. Treated students are asked to measure, each day over a period of one week, the amount of waste generated in their household. Control students face a placebo task of measuring the outdoor temperature. In a subsequent session, treated students listen to a brief lecture on waste and the environment, participate in a subsequent group discussion, and play an educational game. Control students take part in a similar educational session on weather. We then couple the home addresses provided by students with household-level waste data to examine the differential effect of the waste-themed interventions on the waste generated by households where a child was treated.
External Link(s)

Registration Citation

Citation
Ek, Claes, Sandra Samuelsson and Magnus Söderberg. 2023. "Can children’s engagement in recycling processes reduce household waste?." AEA RCT Registry. October 23. https://doi.org/10.1257/rct.3300-2.0
Former Citation
Ek, Claes, Sandra Samuelsson and Magnus Söderberg. 2023. "Can children’s engagement in recycling processes reduce household waste?." AEA RCT Registry. October 23. https://www.socialscienceregistry.org/trials/3300/history/197544
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
1. Treatment: educational package on waste. (i) Home assignment (weighing residual and food waste), (ii) Lecture, group discussion, educational game
2. Placebo control: educational package on weather. (i) Home assignment (measuring temperature, rainfall, etc.), (ii) Lecture, group discussion, educational game
Intervention (Hidden)
Intervention Start Date
2018-09-10
Intervention End Date
2018-12-14

Primary Outcomes

Primary Outcomes (end points)
1) Residual waste amounts (in kilograms), 2) Food waste amounts (in kilograms)
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
All school visits are conducted by the same two experimenters. Each class is visited twice. On the first visit, students within a class are randomized into a treatment and a control condition. Within each condition, students are given an exercise. Treated students are asked to measure, each day over a period of one week, the amount of waste generated in their household or the household they are visiting that day. Control students face a similar task of measuring the outdoor temperature and other weather factors for a consecutive seven days.

Between one and three weeks after the conclusion of these exercises, each class is revisited by the experimenters. In this second session, treated students listen to a brief lecture on waste and the environment, participate in a subsequent group discussion, and finally play an educational game where they answer quiz questions on waste and tasked with correctly sorting cards representing different waste fractions. Control students instead listen to a lecture on geographical variation in temperature and rainfall, and participate in a similarly themed group discussion and quiz.

As part of the home assignment, each student fills in a form provided by the experimenters. This is the main data source from the intervention itself. One of the fields specifies the address where, for each day, the assignment was carried out. These addresses are then combined with household-level waste data, allowing estimation of the differential effect of treatment on waste amounts in the households where a student was treated.
Experimental Design Details
All school visits are conducted by the same two experimenters. Each class is visited twice. On the first visit, students within a class are randomized into a treatment and a control condition. Within each condition, students are given an exercise. Treated students are asked to measure, each day over a period of one week, the amount of waste generated in their household or the household they are visiting that day. Control students face a similar task of measuring the outdoor temperature and other weather factors for a consecutive seven days.

Between one and three weeks after the conclusion of these exercises, each class is revisited by the experimenters. In this second session, treated students listen to a brief lecture on waste and the environment, participate in a subsequent group discussion, and finally play an educational game where they answer quiz questions on waste and tasked with correctly sorting cards representing different waste fractions. Control students instead listen to a lecture on geographical variation in temperature and rainfall, and participate in a similarly themed group discussion and quiz.

As part of the home assignment, each student fills in a form provided by the experimenters. This is the main data source from the intervention itself. One of the fields specifies the address where, for each day, the assignment was carried out. These addresses are then combined with household-level waste data, allowing estimation of the differential effect of treatment on waste amounts in the households where a student was treated. The form also collects information on social networks within classes, allowing us to control for social interaction as a mechanism for behavioral spillovers between treatment and control.
Randomization Method
Assignment into treatment/control: manual shuffling of randomization cards
Assignment of experimenters to treatment/control group: coin flip
Randomization Unit
Treatment/control: Student (within class-randomization). Also, for each class, experimenters were randomly assigned to either treatment or control.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
400 students.
Sample size: planned number of observations
400 students.
Sample size (or number of clusters) by treatment arms
200 students in treatment and control, respectively.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Residual waste: 0.68 kg (6.69%, SD = 9.49) Food waste: 0.46 kg (9.8%, SD = 6.41)
IRB

Institutional Review Boards (IRBs)

IRB Name
Regional Ethical Review Board Gothenburg
IRB Approval Date
2018-12-03
IRB Approval Number
929-18
Analysis Plan

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Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
December 14, 2018, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
March 31, 2019, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
351 addresses
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
7,231 address-by-two-week-period pairs.
Final Sample Size (or Number of Clusters) by Treatment Arms
181 treated addresses, 170 control addresses.
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
No
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials