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Gift-exchange in Society and the Social Integration of Refugees - A Natural Field Experiment
Last registered on June 15, 2020


Trial Information
General Information
Gift-exchange in Society and the Social Integration of Refugees - A Natural Field Experiment
Initial registration date
June 15, 2020
Last updated
June 15, 2020 11:40 AM EDT
Primary Investigator
University of Vechta
Other Primary Investigator(s)
PI Affiliation
Halle Institute for Economic Research & Otto von Guericke University Magdeburg
PI Affiliation
University of Vechta
Additional Trial Information
Start date
End date
Secondary IDs
Refugee integration requires broad support from the host society, but only a minority of the host population is actively engaged. Given that most individuals reciprocate kind behavior, we examine the idea that the proportion of supporters will increase as a reciprocal response to refugees’ contributions to society through volunteering. We ran a nationwide survey experiment, a laboratory experiment and a natural field experiment (the latter is registered here). All data show that citizens’ intentions to contribute time and money as well as actual contributions rise significantly when they learn about refugees’ pro-social activities.
External Link(s)
Registration Citation
Jeworrek, Sabrina, Bernd Leisen and Vanessa Mertins. 2020. "Gift-exchange in Society and the Social Integration of Refugees - A Natural Field Experiment." AEA RCT Registry. June 15. https://doi.org/10.1257/rct.6002-1.0.
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Experimental Details

The treatment texts on the flyers which were on behalf of the Syrian refugee read as follows:
[1] Hello, dear neighbors from [part of town], my name is [typical Syrian first name]. I came to [name of the town] from Syria as a refugee and moved to your neighborhood. Through friends, I learned about [name of the platform]. This is a complimentary internet platform with which neighbors can get to know and support each other in everyday life.
[2] I’m currently volunteering to co-found our digital neighborhood and helping to distribute these flyers to every home in [several parts of town] – that's over 9,000 households ;-). This is my first contribution to a lively neighborhood.
[3] In the next step, I would also like to be available for a direct, mutual exchange of everyday help. If a neighbor could help me to understand a difficult letter, for example, I could help him in return with doing small household or garden tasks.

The control group saw only Paragraph 1, the third-party support treatment group additionally received Paragraph 2, and the mutual support treatment group received all three paragraphs.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Share of registrations.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
We measured the number of registrations for a digital neighborhood community following a flyer campaign. We had 3 different flyer versions.
The random allocation of the three versions resulted in 1,935 flyers for the control group, 2,005 flyers for third-party support treatment group, and 2,140 flyers for mutual support treatment group, so that 6,080 households received a flyer in their mailbox on behalf of a Syrian refugee. Additionally, 1,088 flyers were distributed on behalf of a German neighbor in the third-party support group. In total, 7,166 flyers were distributed regarding this experiment. About 1,800 additional flyers were distributed by and on behalf of other locals who wanted to actively promote the use of the neighborhood platform. So all households in this small city (~9,000) received a flyer invitation.
Experimental Design Details
Randomization Method
Randomization done in office by mixing up the flyers.
Randomization Unit
Individual mailbox
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
7,166 households.
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
1935 flyers for the control group, 2005 flyers for third-party support treatment group, 2140 flyers for mutual support treatment Group by Syrian refugee.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
IRB Approval Date
IRB Approval Number
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)