Pre experiment registration: Debt and Social Comparison
Last registered on November 30, 2018


Trial Information
General Information
Pre experiment registration: Debt and Social Comparison
Initial registration date
November 24, 2018
Last updated
November 30, 2018 11:35 AM EST
Primary Investigator
DIW Berlin
Other Primary Investigator(s)
PI Affiliation
DIW Berlin
Additional Trial Information
On going
Start date
End date
Secondary IDs
The aim of this experiment is to examine whether having to make consumption decisions publically leads people to borrow in order to be able to signal higher status then they actually achieved. Participants are paid depending on their performance in a test that involves questions designed to measure intelligence. Participants that perform well on the test are able to buy better quality pens. Participants that perform less well are can still buy better quality pens, but have to take a loan for this. There are three treatments, in the first treatment the decision is taken privately on the computer, in a second treatment participants have to announce their choices publically, in a third treatment participants make their decisions on a computer, but can see the choices participants in the same session took. The shopping round is followed by a slider task. We test if participants in different treatment work harder in order to earn more following the shopping round.
External Link(s)
Registration Citation
Grohmann, Antonia and Melanie Koch. 2018. "Pre experiment registration: Debt and Social Comparison." AEA RCT Registry. November 30.
Experimental Details
There are three treatments:
(i) Private treatment - respondents make choices on computer
(ii) Public treatment – respondents make choices on computer but announce out loud.
(iii) Information treatment – participants make decisions on computer but can see choices make by others.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
There are three outcome variables:
1. Debt taken in shopping round – we will use a between subject design to examine the difference in the borrowing and the amount borrowed between subjects in the three treatments.
2. Amount of money earned/amount of sliders set in slider task – we will use a between subject design to study how many sliders participants completed and how much money they earned.
3. Deviation from choices made in survey prior to experiment - Prior to the experiment participants were asked to answer a short questionnaire about the preferences regarding several products. We will use a within subject design to study whether subjects deviate from their original choice. We will correlate deviation with a large number of psychological variables to measure susceptibility to social comparison.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
At the beginning of the experiment subjects come into the lab and are given detailed instructions. Subjects are told that there are rounds during which they can earn money. (i) is an IQ style test during which they can earn money according to their position compared to other participants. (ii) is an income earning round during which their earning depend on their performance alone.
(i) Subjects earn money according to their performance compared to others participants in the lab. They have to spend this income on a pen. Pens come in different prices and in different qualities. Participants can borrow money to buy higher quality pens then they could afford due to their income. There are three different treatments for different ways that people communicate their choice of pen.

(ii) The second income round is a slider task. Subject’s earnings only depend on their own performance in the slider task.
The two income rounds are followed by a questionnaire during which we ask a large number of psychological questions.
Experimental Design Details
Randomization Method
Computerised Randomisation
Randomization Unit
experimental session
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
27 (including pilot sessions)
Sample size: planned number of observations
324 (including pilot sessions)
Sample size (or number of clusters) by treatment arms
108- Treatment 1
108- Treatment 2
108 – Treatment 3
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Hypothesized behavior for the control group (treatment1) leads to the following minimum detectable effect size: (i) Amount borrowed: ~0.38 (ii) Amount sliders set in slider task: ~0.38
Supporting Documents and Materials

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