Peer Pressure To Drink

Last registered on September 26, 2025
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Pre-Trial

Trial Information

General Information

Title
Overcoming Peer Pressure To Drink
RCT ID
AEARCTR-0016852
Initial registration date
September 22, 2025

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
September 26, 2025, 8:09 AM EDT

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

Locations

Country
Germany
Region

Primary Investigator

Name
Manuel Hoffmann
Affiliation
University of California, Irvine
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Other Primary Investigator(s)

PI Name
Bernd Josef Leisen
PI Affiliation
University of Vechta
Contact Investigator
PI Name
Vanessa Mertins
PI Affiliation
University of Vechta
Contact Investigator

Additional Trial Information

Status
Completed
Start date
2018-12-19
End date
2022-05-19
Keywords
Behavior
Additional Keywords
Peer Pressure, Field Experiment, Health Behavior, Alcohol
JEL code(s)
C93, I12, D90, H0
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We study how to overcome peer pressure to drink through a series of field experiments in Germany. We randomly provide feedback to individuals about their peer and own alcohol levels to better understand whether individuals converge to the average consumption of their peers. We further provide monetary incentives to strengthen single group members to resist peer pressure to drink and incentivizing all group members to reduce drinking. In further field experiments, we measure the social value of drinking within groups and test the impact of feedback in combination with an auction-like mechanism. In particular, we measure the willingness to abstain from drinking to better understand how the value of peer pressure may change behavior. Finally, in a third experiment we offer an instrument to exert peer pressure to individuals in an online drinking setting to better understand whether direct peer pressure can be a mechanism for indirect peer pressure.
External Link(s)

Registration Citation

Citation
Hoffmann, Manuel, Bernd Josef Leisen and Vanessa Mertins. 2025. "Overcoming Peer Pressure To Drink." AEA RCT Registry. September 26. https://doi.org/10.1257/rct.16852-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Our main outcome variable for indirect peer pressure is the change in individual intoxication relative to peer intoxication over time, where peer intoxication is measured by the peer mean.

This outcome specification allows us to account for different baseline levels of drinking upon entry into the event locations and to better understand the process of individual and peer consumption over time. Naturally, this is identical to the difference in the change in the individuals’ own alcohol level relative to the change in the average alcohol level of their peers,
Intervention Start Date
2018-12-19
Intervention End Date
2022-05-19

Primary Outcomes

Primary Outcomes (end points)
Experiment I. Our main outcome variable is the change in individual relative to peer intoxication over time
Experiment II. Our main outcome variable is the individual relative to peer willingness to abstain
Experiment III. Our main outcome variable is the individual relative to peer offer to abstain from drinking received by peers
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Experiment I. Own intoxication, Peer Intoxication
Experiment II. Own Willingness to Abstain, Peer Willingness to Abstain
Experiment III. Own Offer to Abstain from Drinking Received by Peers, Peer Offer to Abstain from Drinking Received by Peers
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
This study contains three field experiments with a series of settings for individuals who are actively drinking within groups. We introduce feedback as a major intervention to study how to measure and overcome peer pressure in the context of alcohol consumption.

Randomized field experiment I:
- No Feedback: individuals receive feedback only upon exiting the event
- Live Feedback to individuals upon entering the event
- Live Feedback + Monetary incentive to drink below the peer average for one randomly selected individual upon entering the event
- Live Feedback + Monetary incentive to drink below the peer average for one randomly selected individual upon exiting the event

Randomized field experiment II:
- No Feedback: Individuals receive feedback only after stating their willingness to abstain from a BDM auction mechanism
- Live Feedback: Individuals receive feedback before stating their willingness to abstain from a BDM auction mechanism

Randomized field experiment III:
- No Feedback: peers state their consumption privately
- Live Feedback: peers state their consumption publicly

Feedback always includes information on individuals about their peer and own alcohol levels from breathalyzer tests (I/II) or from stated consumption (III). In the first two experiments the groups are endogenous while they are randomly assigned in the third experiment.

Experiment 1 is conducted in bars, discos, festivals and at parties. Experiment 2 is conducted at parties and pre-gaming events as well as on May 1st, a nationwide German holiday during which many groups practice heavy day drinking. Experiment 3 is in online drinking settings.
Experimental Design Details
Randomization Method
Randomization done in office by a computer
Randomization Unit
All Experiments: Group Level
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
Experiment I: 120 groups
Experiment II: 40 groups
Experiment III: 50 groups
Sample size: planned number of observations
Experiment I: 360 group members Experiment II: 120 group members Experiment III: 150 group members
Sample size (or number of clusters) by treatment arms
Experiment I: Treatment 1 52, Treatment 2 82, Treatment 3 66, Treatment 4 86
Experiment II: Treatment 1 66 Treatment 2 92
Experiment III: Treatment 1 107, Treatment 2 100
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
German Association for Experimental Economic Research
IRB Approval Date
2018-12-19
IRB Approval Number
VsYNeXGf
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
May 19, 2022, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
May 19, 2022, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials