Break the Norm: An Experiment on Opinion Leaders and Homophily

Last registered on February 19, 2025
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Pre-Trial

Trial Information

General Information

Title
Break the Norm: An Experiment on Opinion Leaders and Homophily
RCT ID
AEARCTR-0015044
Initial registration date
December 17, 2024

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
February 19, 2025, 8:38 AM EST

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

Locations

Country
Italy
Region

Primary Investigator

Name
Xin Zhang
Affiliation
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2024-12-17
End date
2024-12-20
Keywords
Behavior
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Social norm evolution is essential to the development of society but can be blocked by norm entrenchment. Opinion leaders, distinguished by their increased media coverage and superior information access, possess the capacity to catalyze norm-breaking through endorsement; however, their actions are contingent upon individual motives. This study explores the influence of opinion leaders, specifically examining how those informed by general social preferences regarding a given norm contribute to steering society toward the socially optimal path—or not—across various circumstances. We adapt the theoretical model based on Gallice and Grillo (2020) and design a laboratory experiment, to provide valuable feedback to refine existing theoretical frameworks.
External Link(s)

Registration Citation

Citation
Zhang, Xin. 2025. " Break the Norm: An Experiment on Opinion Leaders and Homophily." AEA RCT Registry. February 19. https://doi.org/10.1257/rct.15044-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Participants are divided into fixed matching group taking the roles mimicking the opinion leader (Gray player) and individuals (Purple players) who have the preference on violating the social norm. Then the Gray player will get the information about the composition of the society which can determine whether it's beneficial for the Purple player to reveal their preference.
Intervention Start Date
2024-12-17
Intervention End Date
2024-12-20

Primary Outcomes

Primary Outcomes (end points)
The probability of opinion leader choosing to endorse and the probability the potential violators choosing to follow the endorsement
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment will be conducted in person in the lab. There will be three treatments which differ in payoff structure and matching scheme of the participants.
Experimental Design Details
The experiment consists of three treatments: Baseline, IDEO, and HOMO. In the Baseline treatment, the gray player acts as an opinion leader without any ideological preference regarding the social norm. They will only benefit from encouraging Purple players to violate the norm if the Purple players are the majority in the society and some of them choose to follow the encouragement. In the IDEO treatment, the opinion leader has a preference for violating the prevailing social norm, and will benefit from encouraging violations as long as at least some Purple players choose to violate, regardless of whether they are the majority in the society. The HOMO treatment differs from IDEO in that Purple players interact more within their group, reducing the likelihood of being punished by individuals who prefer to abide by the social norm.
Randomization Method
by computer
Randomization Unit
5-subject group
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
28 groups = 140 subjects
Sample size: planned number of observations
28 groups = 140 subjects
Sample size (or number of clusters) by treatment arms
4 groups for baseline treatment and 12 groups each for IDEO and HOMO treatments
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
University of Bologna - Comitato di Bioetica
IRB Approval Date
2024-06-05
IRB Approval Number
0156346
Analysis Plan

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Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials