Magical Thinking and Self-Similarity

Last registered on September 19, 2022

Pre-Trial

Trial Information

General Information

Title
Magical Thinking and Self-Similarity
RCT ID
AEARCTR-0008288
Initial registration date
September 23, 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
September 28, 2021, 4:04 PM EDT

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

Last updated
September 19, 2022, 2:22 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
Stockholm School of Economics

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2021-09-27
End date
2022-07-01
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This experiment investigates the role of magical thinking in binary dictator games. In a 2x2 treatment design, subjects are randomly allocated across two treatment dimensions: Roles and Similarity. The Roles dimension varies whether subjects are matched in traditional giver-receiver pairs (Single Role) or whether they are matched with two other participants, playing as Dictator against one and as Receiver against the other. (Dual Role). The Similarity dimension varies whether subjects are matched randomly, or matched with others who are especially similar to themselves based on a personality test. I hypothesize that there is a positive interaction effect between these two treatments on giving behavior.
External Link(s)

Registration Citation

Citation
Semb, Joakim. 2022. "Magical Thinking and Self-Similarity." AEA RCT Registry. September 19. https://doi.org/10.1257/rct.8288-1.1
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2021-09-27
Intervention End Date
2021-09-28

Primary Outcomes

Primary Outcomes (end points)
Giving in binary-decision dictator games
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
First, all subjects take a personality test constructed from 120 IPIP items.

Then, in a 2x2 treatment design, subjects are randomly allocated across two treatment dimensions: Roles and Similarity. The Roles dimension varies whether subjects are matched in traditional giver-receiver pairs (Single Role) or whether they are matched with two other participants, playing as Dictator against one and as Receiver against the other. (Dual Role). The Similarity dimension varies whether subjects are matched randomly, or matched with others who are especially similar to themselves based on a personality test.

Participants (except receivers in Single Role conditions) then make 20 binary allocation decisions, choosing between two allocations between themselves and their matched partner.

The parameter of interest is the interaction between similarity and roles: does role duality increase giving more when the degree of self-similarity is higher?
Experimental Design Details
Randomization Method
Computer randomization
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
1200 decision-making participants, plus 600 receivers
Sample size: planned number of observations
1200 decision-making participants, plus 600 receivers. 20 decisions per decision-making participant.
Sample size (or number of clusters) by treatment arms
300 decisionmakers in each of the four treatment cells.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

Analysis Plan

MD5: 2f8192b152f69b224c221b805fd2310f

SHA1: 6d4baffa657b639690d5e4be69f02e7a93fd535f

Uploaded At: September 23, 2021

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