Quantifying the role of greenhouse gas emissions in consumption choice

Last registered on January 17, 2025

Pre-Trial

Trial Information

General Information

Title
Quantifying the role of greenhouse gas emissions in consumption choice
RCT ID
AEARCTR-0007858
Initial registration date
June 21, 2021

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
June 22, 2021, 10:09 AM EDT

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

Last updated
January 17, 2025, 3:20 PM EST

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

Locations

Region

Primary Investigator

Affiliation
University of Bonn

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2021-06-22
End date
2024-06-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The goal of this project is to provide insights into food consumption choices in the presence of greenhouse gas emissions. This will be investigated in an experiment studying incentivized choices between different restaurant meal options. The experimental conditions vary in the information which is provided to participants at the moment of choice.
External Link(s)

Registration Citation

Citation
Schulze Tilling, Anna. 2025. "Quantifying the role of greenhouse gas emissions in consumption choice." AEA RCT Registry. January 17. https://doi.org/10.1257/rct.7858-1.2
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Experimental sessions are planned in June and July 2021. In each session, participants first fill out a survey online (45 minutes duration) and then pick up their payment in person on the same day and no later than 2 pm. In addition to their payment, participants receive a meal for immediate consumption when picking up their payment. Participants make a total of 15 meal choices in the course of the survey. In each choice, they state which of two meals they prefer and their maximum WTP to receive the preferred meal. The treated group is provided with carbon emission labels of the meals in some of the choices. Further, in some other choices, the carbon emissions caused by the meals chosen by participants are offset with a respective donation to atmosfair. In addition to the meal choices, the survey asks participants for their WTP for emission labels. In both the meal choices and WTP-elicitation for information, participants are incentivized to state their true WTP. The survey also gathers information on demographics, environmental attitudes, guesses on the amount of emissions attributable to each meal, and psychological characteristics.
Intervention Start Date
2021-06-22
Intervention End Date
2021-07-23

Primary Outcomes

Primary Outcomes (end points)
The effect of providing carbon emission labels on meal choices, the effect of carbon offsetting on meal choices
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Participants are randomly sorted into either one of the two treated groups or the control group. Depending on the treatment group participants are assigned to, the information conditions under which they make consumption decisions in the core part of the survey differ. In the course of the survey, participants’ willingness to pay (WTP) for various restaurant meals is elicited under different conditions. In one information condition, participants are shown the greenhouse gas emissions caused by each meal.
Experimental Design Details
Randomization Method
Treatment conditions are randomly assigned by the survey software.
Randomization Unit
individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
300-600 individuals
Sample size: planned number of observations
300-600 individuals
Sample size (or number of clusters) by treatment arms
100-200 control, 200-400 treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Due to the fact that the experiment procedure differs from usual procedures at the BonnEcon-Lab and that some potential participants may not physically be in Bonn due to the Covid-19 pandemic, it is difficult to predict how successful recruitment will be. I plan for a minimum of 300 and an ideal number of 600 participants. Power calculations based on a pre-survey suggest that a sample size of 300 participants will yield power of over 80% for the main outcomes. The MDE for change in WTP induced by labels interacted with meal greenhouse gas emissions is 0.278 Euros, which is 17% of average WTP in the hypothetical pre-survey. The MDE for change in WTP induced by offsetting interacted with expected greenhouse gas emissions is 0.024 Euros, which is 1.5% of average WTP in the hypothetical pre-survey.
IRB

Institutional Review Boards (IRBs)

IRB Name
German Association for Experimental Economic Research
IRB Approval Date
2021-06-26
IRB Approval Number
BnyKWhHQ
Analysis Plan

Analysis Plan Documents

Pre-Analysis Plan: Quantifying the role of greenhouse gas emissions in consumption choice

MD5: 1ecc49520ecd5c787c2d37de8fac14b1

SHA1: 89c96b1ace58615b1b8892f5ace17ea848014894

Uploaded At: June 21, 2021

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials