AEA RCT Registry

Trial Information

General Information

Title

Personal and social norms effects on pro-environmental behavior

RCT ID

AEARCTR-0014072

Initial registration date

August 08, 2024

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

August 14, 2024, 2:23 PM EDT

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

Locations

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Primary Investigator

Name

Pau Balart

Affiliation

Universitat de les Illes Balears

Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status

In development

Start date

2024-07-01

End date

2026-11-30

Keywords

Environment & Energy

Additional Keywords

social norms, personal beliefs, environmental behavior, recycling

JEL code(s)

Secondary IDs

Prior work

This trial does not extend or rely on any prior RCTs.

Abstract

Our study aims to analyze the role of social norms for recycling. The study has two stages. In the first stage, we will run an online survey to collect information on personal and social norms. In the second stage, we will run a field experiment to analyze if providing information about others' social norms can affect participation in waste sorting.

Citizens of Palma must scan a card that identifies them in order to use the bins meant for bio-waste sorting. We partnered with the city's waste management company to get access to such data. The main goal is to study how the participants' use of the bio-waste sorting bins is affected by beliefs on prescriptive social norms and by receiving information about others’ beliefs on these norms. The participants will be randomly allocated to control (no information on prescriptive social norms) or treatment group (information on prescriptive social norms).

External Link(s)

Registration Citation

Citation

Balart, Pau. 2024. "Personal and social norms effects on pro-environmental behavior." AEA RCT Registry. August 14. https://doi.org/10.1257/rct.14072-1.0

Sponsors & Partners

Partner

Name

EMAYA

Type

municipality

URL

https://www.emaya.es/es

Experimental Details

Interventions

Intervention(s)

Our study aims to analyze the role of social norms for recycling. The study has two stages. In the first stage, we will run an online survey to collect information on personal and social norms. In the second stage, we will run a field experiment to analyze if providing information about others' social norms can affect participation in waste sorting.

Intervention Start Date

2025-03-02

Intervention End Date

2026-03-31

Primary Outcomes

Primary Outcomes (end points)

Dummy variable that indicates for each week whether the household used the bio-waste sorting bin (1) or not (0)

Primary Outcomes (explanation)

If averaging the primary dummy variable over time for each household, we obtain the proportion of weeks that each household makes use of bio-waste sorting bins.
If aggregating the primary dummy variable across households on a given week, we obtain the proportion of households that make use of bio-waste sorting bins on that week.

Secondary Outcomes

Secondary Outcomes (end points)

Besides real behavior (recycling) we will also capture intentions to act and changes about others' beliefs by two self-reported answers (asked after providing the information on others' social norms in the case of the treated group) The item for intentions to act, asks about the intention to recycle (5 possible answer from "totally disagree" to "totally agree"). The item about others' beliefs asks for "Out of every 10 people surveyed, how many do you think respond that they "agree" or "totally agree" with the statement "I consider that people who does not recycle should be penalized with fines"? (11 possible answers from 0 out of 10 to 10 out of 10).

Secondary Outcomes (explanation)

Experimental Design

Our study adapts the experiment by André et al (2024) to a field intervention where we can directly observe waste sorting by participating households.

Experimental Design Details

Not available

Randomization Method

For the second stage of the study (experiments) participants are recruited face-to-face and will be allocated upon order of arrival to the control and treatment groups subsequently. That is, on a given day, the first participant will be allocated to the control group, the second to the treatment group, the third to the control and so on and so forth (zipper strategy).
For balancing tests, pre-intervention values of the primary outcome will be used.

Randomization Unit

Participating households

Was the treatment clustered?

No

Experiment Characteristics

Sample size: planned number of clusters

First part (online questionnaire) between 100 and 800 households.
Second part (experiment) between 500 and 2500 households.

Sample size: planned number of observations

First part (online questionnaire): between 100 and 800 households. Second part (experiment): between 500 and 2500 households.

Sample size (or number of clusters) by treatment arms

Number of weeks * Number of households

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

According to data from our studies in the same setting, the average household in our study uses bio-waste sorting bins with a weekly frequency of 0.1876207, showing a standard deviation of 0.324002. For a power analysis of 80%, a sample size of at least 500 households per treatment arm guarantees a minimum detectable effect of 0.0610 in the use frequency at 95% confidence and 0.0745 at 99% confidence.

Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name

Comité d'Ética de la Recerca (CER) de la Universitat de les Illes Balears

IRB Approval Date

2024-07-09

IRB Approval Number

38CER24

Analysis Plan

Analysis Plan Documents

Pre-Analysis Plan

MD5: 2d257de0b56b16cdc42654de507e845d

SHA1: e478521c432c79ac25ab41f931268dc7312e0b35

Uploaded At: August 08, 2024