Not that way! An Exploration of the Social Free-rider Problem as Cause of the Boomerang Effect from Social Norm Information

Last registered on October 15, 2021


Trial Information

General Information

Not that way! An Exploration of the Social Free-rider Problem as Cause of the Boomerang Effect from Social Norm Information
Initial registration date
October 11, 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
October 15, 2021, 10:19 AM EDT

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



Primary Investigator

Escuela Superior Polit├ęcnica del Litoral

Other Primary Investigator(s)

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Social norms information is often used to nudge people towards prosocial behavior, yet, seldom results are unexpected and end in a boomerang effect that can potentially cause unintended harm. While there have been several explanations for why boomerang effects occur, the standard literature not always provide successful explanations. As these nudges are often used in campaigns of societal importance, it is valuable to understand under what circumstances the boomerang effect will occur. One cause of a boomerang effect that we explore is a social free-rider problem whereby the social norm information acts as a mechanism of updating prior probabilities on the actions of others. In this study, we formally propose a model of the social free-rider problem in the context of the boomerang effect from social norm information. Furthermore, we test our model predictions in a laboratory experiment through a modified dictator game with the option for punishment.
External Link(s)

Registration Citation

Rhodes, Lauren. 2021. "Not that way! An Exploration of the Social Free-rider Problem as Cause of the Boomerang Effect from Social Norm Information." AEA RCT Registry. October 15.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Punishment of Dictator.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
A Dictator will have the option to evenly split their EMUs among their group, or keep all EMUs for themselves. The other players will then have the option to punish the Dictator if the even split option was not chosen. Have of the non-Dictator participants who have the option to punish will receive social norm information on the appropriateness of the behavior of of the Dictator.
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
Randomized at the individual level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
The treatment is not clustered.
Sample size: planned number of observations
600 participants
Sample size (or number of clusters) by treatment arms
We will have approximately 150 Dictator observations which are not subject to the treatment. Of the remaining 450 participants, 225 will be assigned to the treatment group and 225 will be assigned to the control group.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials