The American Economic Association's registry for randomized controlled trials
Please fill out this
short user survey
of only 3 questions in order to help us improve the site. We appreciate your feedback!
Reciprocity: Warm glow or guilt aversion?
Last registered on January 27, 2021
View Trial History
Reciprocity: Warm glow or guilt aversion?
Initial registration date
November 30, 2020
January 27, 2021 8:11 AM EST
United States of America
University of Innsbruck
Contact Primary Investigator
Other Primary Investigator(s)
Victoria University of Wellington
Additional Trial Information
We utilize the trust game to investigate in an online experiment whether trustees (receivers) who send money back are rather motivated by positive feelings such as warm glow or by avoiding negative feelings such as guilt. In the trust game itself, distinguishing between altruism and guilt aversion is senseless as both higher levels of altruism and higher levels of guilt aversion motivate the receiver to return higher amounts. However, distinguishing between the two kinds of motivations is important when receivers can opt out from the trust game. Specifically, we have developed a behavioral game theoretic model that yields the following main result: If reciprocal behavior is motivated by guilt aversion (warm glow), then those who return higher amounts have a higher (lower) incentive to opt out. Distinguishing between warm glow and guilt aversion is hence important to understand if and why subjects who self-select or who are randomly assigned to situations where trust matters behave more or less trustworthy. A pilot with 200 subjects suggests that reciprocity seems to be motivated by positive emotions (warm glow) rather than by avoiding negative emotions (guilt).
Feess, Eberhard and Florian Kerzenmacher. 2021. "Reciprocity: Warm glow or guilt aversion?." AEA RCT Registry. January 27.
Sponsors & Partners
Intervention Start Date
Intervention End Date
Primary Outcomes (end points)
Our primary outcome is whether subjects in the role of trustees decide to participate in a trust game.
Primary Outcomes (explanation)
Secondary Outcomes (end points)
Secondary Outcomes (explanation)
The experiment will be conducted online and participants will be recruited using Amazon Mechanical Turk.
Subjects will be randomly assigned to groups of two. The two group members are randomly assigned the roles of trustor (sender) and trustee (receiver).
In addition to the participation fee, trustors receive $0.50. They have to decide whether they want to keep this amount or send it to the trustee. If they decide to give it to the trustee, the amount is tripled and the trustee receives $1.50. The trustee can then decide how much money to send back to the trustor (between $0 and $1.50).
The amount the trustee wants to send back will be elicited according to the strategy method assuming that the trustor has sent the money. After trustees make their decision, they will be given an exit option. If they decide to not play the trust game, they receive a certain payment of $0.50 in addition to their participation fee. In this case, trustors simply keep their additional $0.50.
Following this baseline setting, we plan to conduct another treatment in which trustees are informed about the frequency of trustors sending the money in the previous treatment in order to fix beliefs.
Experimental Design Details
Participants will be randomly assigned to groups and roles (computerized).
Individual level randomization.
Was the treatment clustered?
Sample size: planned number of clusters
Sample size: planned number of observations
We plan to collect 880 observations, i.e. 880 participants.
Sample size (or number of clusters) by treatment arms
We plan to collect 440 observations in the baseline treatment and 440 observations in the other treatment.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
In a pilot experiment with 200 participants (100 trustees), a logit regression revealed a positive impact of the amount trustees intend to give to trustors on their participation decision (p=0.279, including controls about the beliefs on the behavior of trustees, gender, age, and risk attitude). The probability of the mean amount sent back participating was at 65% and the probability of the mean plus one standard deviation amount sent back participating was at 72%. Assuming this effect prevails, a logit regression power analysis reveals that we need about 220 observations of trustees (one-tailed test, 5% significance level, 80% power). UPDATE: Adjustment of sample size: We have collected 220 observations for trustees in each of the two treatments. In line with our pilot, the impact of the returned amount on the participation decision is always positive, both with non-parametric and parametric analyses. However, depending on the combination of control variables, the amount is sometimes significantly positive at the 5%-level and sometimes barely insignificant at the 10% level, so that no robust conclusions can be drawn yet. We therefore decided to increase the statistical power by doubling the number of observations to see whether results prevail.
Supporting Documents and Materials
INSTITUTIONAL REVIEW BOARDS (IRBs)
Board for Ethical Questions in Science of the University of Innsbruck
IRB Approval Date
IRB Approval Number
Post Trial Information
Is the intervention completed?
Is data collection complete?
Is public data available?
Reports, Papers & Other Materials
REPORTS & OTHER MATERIALS