Market Discrimination and Social Media

Last registered on May 17, 2023


Trial Information

General Information

Market Discrimination and Social Media
Initial registration date
May 07, 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
May 07, 2021, 10:32 AM EDT

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

Last updated
May 17, 2023, 2:16 PM EDT

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



Primary Investigator

University of Tuebingen

Other Primary Investigator(s)

PI Affiliation
University of Tuebingen
PI Affiliation
University of Tuebingen

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
We conduct a correspondence test in the market for shared housing to identify the magnitude of ethnic and gender discrimination and the role of personal information posted on a social media platform. About 4,900 fictitious applications with a randomly assigned Turkish-, or German-sounding female or male name will be sent to vacant room ads. In addition, we randomly add a link to a social media profile to determine the effect of such personal information on callback rates. We carefully constructed these fictional social media accounts on Instagram for over the course of two years to make them as realistic as possible, conducting several surveys among young people to ensure that the profiles are close to reality with a sufficient number of followers. Unlike previous research, we can approximate whether landlords or roommates actually visit these profiles and exploit this information using statistics on profile visits and page impressions.
External Link(s)

Registration Citation

Moritz, Raphael, Christian Manger and Kerstin Pull. 2023. "Market Discrimination and Social Media." AEA RCT Registry. May 17.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Callback rates conditional on ethnicity, gender and social media information
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We use a non-matched pair randomized controlled trial (correspondence test design) to test for ethnic and gender discrimination in the market for shared housing in Germany. To do this, we randomly vary the applicant’s name, which signals an ethnic minority or ethnic majority member, and we randomly vary gender. In addition, we vary the amount of information by randomly providing a link to a social media profile that contains additional information about the applicant.
Experimental Design Details
Randomization Method
Computer generated (pseudo) randomization using a Python program
Randomization Unit
Individual level
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
Assuming a 44% percent overall callback rate (from pre-study) we will send out approximately 620 applications for each of the eight treatment groups (immigrant/native*female/male*with/without social media info), resulting in 1,240 applications per treatment arm.
Note that the initial sample size (see above) was higher in a previous version of this pre-registration because we decided to split the trial into two parts after the first trial was completed. We submitted a new pre-registration for the second study (see AEARCTR-0011322).
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethics Committee of the Faculty of Economics and Social Sciences of the Eberhard Karls University Tübingen
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
January 31, 2022, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
January 19, 2022, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
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?

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Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials