Contact and the Price of Prejudice

Last registered on March 16, 2026
View Trial History

Pre-Trial

Trial Information

General Information

Title
Contact and the Price of Prejudice
RCT ID
AEARCTR-0018089
Initial registration date
March 13, 2026

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
March 16, 2026, 7:08 AM EDT

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

Locations

Country
Japan
Region

Primary Investigator

Name
Gwen-Jiro Clochard
Affiliation
Institute of Social and Economic Research - Osaka University
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Andreas Andersen
PI Affiliation
University of Oslo
Contact Investigator
PI Name
Guillaume Hollard
PI Affiliation
Ecole polytechnique, CREST and CNRS
Contact Investigator
PI Name
Andreas Kotsadam
PI Affiliation
Frisch Centre for Economic Research, University of Oslo
Contact Investigator

Additional Trial Information

Status
In development
Start date
2026-03-16
End date
2026-03-27
Keywords
Crime, Violence, & Conflict, Lab, Labor
Additional Keywords
contact hypothesis, discrimination, experiments
JEL code(s)
J15, C92
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We conduct a laboratory experiment at the University of Osaka to test whether brief cooperative contact with an outgroup member reduces the willingness to pay for same-ethnicity coworkers. The design combines the price-of-prejudice paradigm of Hedegaard and Tyran (2018) with a randomized contact round: Japanese subjects are paired with either a Japanese or an international student for a joint production task, and then make 30 incentivized binary choices between potential partners whose nationality and productivity are revealed.
External Link(s)

Registration Citation

Citation
Andersen, Andreas et al. 2026. "Contact and the Price of Prejudice." AEA RCT Registry. March 16. https://doi.org/10.1257/rct.18089-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The intervention will consist in making subjects work in pairs. Pairs will be randomly allocated to be same-group (Japanese-Japanese, control group) or cross-group (Japanese-foreigner, treatment).
Intervention (Hidden)
Intervention Start Date
2026-03-16
Intervention End Date
2026-03-27

Primary Outcomes

Primary Outcomes (end points)
1) Probability of choosing a lower-productivity Japanese partner
2) Willingness to pay to choose same-ethnicity worker.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Price-elasticity of the demand for discrimination.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experimental design resembles that of Hedegaard and Tyran (2018), with an intermediate period of contact. Subjects will perform a real effort task individually for 12 minutes, with a piece-rate reward system. The task will be to stuff envelopes. Individual productivity will be recorded.
After this initial productivity measure, subjects will be randomly paired. Because we ensure that approximately 25% of the subjects in each session (3 subjects for a session of 12 people) are foreign, by design approximately 6 Japanese students will be allocated to the control group (paired with another Japanese student) and 3 will be allocated to the treatment group (paired with an international student).
The pairs will perform the same task as in the individual production for 12 minutes, except that pairs will be paid collectively, with a joint production function. Pairs will be encouraged to discuss during the contact phase.
After the intervention, all participants will answer a set of questions which will be used to measure their willingness to pay to discriminate (see outcomes).
Experimental Design Details
Randomization Method
Lottery of ids at registration (cards in an envelope)
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
200 individuals
Sample size: planned number of observations
200 individuals
Sample size (or number of clusters) by treatment arms
Approximately 130 subjects in control, 70 in treatment.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
2.5-3.7 tau units, see PAP
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Institute of Social and Economic Research, The University of Osaka, Research Ethics Committee
IRB Approval Date
2026-01-30
IRB Approval Number
20260104
Analysis Plan

Analysis Plan Documents

Contact_and_price_of_discrimination_PAP.pdf

MD5: ea70e28a184d80dfeb01da3be8e37346

SHA1: a3e50be7be4440d06ba8b43a34513fe2eb577efe

Uploaded At: March 13, 2026

Post-Trial

Post Trial Information

Study Withdrawal

There is information in this trial unavailable to the public. Use the button below to request access.

Request Information

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