Group-Biased Risk Perception

Last registered on June 17, 2021


Trial Information

General Information

Group-Biased Risk Perception
Initial registration date
June 16, 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
June 17, 2021, 2:36 PM EDT

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



Primary Investigator

University of Pittsburgh

Other Primary Investigator(s)

Additional Trial Information

In development
Start date
End date
Secondary IDs
This study investigates how the grouping structure of information about others' outcomes in a risky environment with uncertain prospects affects individuals' beliefs about their own prospects. In particular, the study is focused on environments where an individual's risk is not meaningfully predicted by their group. Applying insights from prior literature on in-group/out-group biases in behavioral economics, the underlying hypothesis of this study is that individuals overweight information about in-group others relative to information about out-group others as a heuristic, even in the absence of a plausible reason to believe prospects are determined by group. As a result, with sufficiently small samples of information, individuals may have incorrect beliefs about their own prospects which lead them to take on a suboptimal amount of risk relative to their own preferences. Applications to health and environmental topics will be discussed.
External Link(s)

Registration Citation

Hyde, Kelly. 2021. "Group-Biased Risk Perception." AEA RCT Registry. June 17.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
- Choice between a sure payment and a lottery with uncertain prospects (i.e., a context-specific measure of risk preferences)
- A belief elicitation about one's own prospects in that lottery based on the information they receive.
Primary Outcomes (explanation)
The lottery with uncertain prospects is defined to participants as follows: they have been randomly assigned an integer value X from the uniform distribution between 0 and 100, as has everyone else in the same session. The choice is done through a price list with a gradually increasing sure payment between $0 and $5 and the lottery, which is an X% (unknown to the participant) chance of earning $5 and a (1-X)% chance of earning nothing. The choice endpoint is their switching point between the sure payment and the lottery. The belief elicitation is about the X they have been assigned.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Individuals in the study will complete multiple experimental stages. The first stage is randomly assigned between 3 possibilities, each of which is designed to prime a particular type of group identification among participants. The second stage is a price list of choices between a lottery with uncertain prospects (a probability of winning unknown to the participant) and a gradually increasing sure payment. The third stage is a traditional allocator game used to measure the individual's degree of in-group bias.
Experimental Design Details
Individuals will be assigned to groups of 4 based on their gender (male or female). It will be known to participants that all other members of their own group are of the same gender as them. The possibilities for stage 1 are as follows: a gender differences questionnaire in which participants guess the respective percentages of American men and women to which a particular statement applies with a payment based on accuracy and chance (BSR method), based on data from 2018 drawn from the General Social Survey and health-related statistics published by the CDC, intended to prime participants to think about differences between men and women in general; a real-effort button pressing task with a group-based incentive that requires every individual in the group to meet a particular point threshold to earn everyone in the group a bonus; or nothing (skipped) as a control condition. Stages 2 and 3 are identical for all participants regardless of assigned Stage 1.

In Stage 2, participants are provided with information in the form of a "test run" of the lottery with uncertain prospects for others in the same session. Essentially, this "test run" takes the X values (unknown to participants) assigned to others in the individual's own group as well as the values assigned to 3 randomly assigned members of a different gender (and thus of a different group) and runs a hypothetical lottery based on those values. Information is then presented by group. In other words, participants are told the following: if the three members of your group and three randomly selected members of a different group chose the lottery, group member 1 would have won, group member 2 would have lost, etc. This information is presented to individuals in a table where one column corresponds to their group mates and the other column corresponds to the outcomes of the other group. To address the possibility of salience confounding any results, the order of these columns is randomized at the individual level so that some see their own group on the left column and others see their own group on the right column. After this information is displayed, individuals are asked what they believe their own X is, and then are asked to complete a price list with gradually increasing sure payments and the lottery based on that choice. One row of the price list is randomly selected for implementation in their payment.

Participants also answer a brief survey, including questions about the strength of their gender identity ("How strongly do you identify with others of the same gender?") and their beliefs about the significance of demographics in the real world ("Please indicate how much you agree with the following statement: In general, the risks people face in life are determined by their demographic characteristics."). These measures will be used for subgroup analyses.
Randomization Method
Randomization done in office by a computer
Randomization Unit
The stage 1 is randomized at the lab session level. The chance of winning the lottery with uncertain prospects is randomized at the individual level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
288 individuals divided into 9 sessions of 32 participants each, with 8 groups (4 of men and 4 of women) in each session
Sample size: planned number of observations
288 individuals
Sample size (or number of clusters) by treatment arms
96 participants in each possible stage 1 (gender differences questionnaire, real effort task, or nothing)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
University of Pittsburgh Institutional Review Board
IRB Approval Date
IRB Approval Number


Post Trial Information

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

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Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials