A replication of the disjunction effect in the prisoners' dilemma

Last registered on September 19, 2022
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Pre-Trial

Trial Information

General Information

Title
A replication of the disjunction effect in the prisoners' dilemma
RCT ID
AEARCTR-0007917
Initial registration date
July 04, 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
July 06, 2021, 10:43 AM EDT

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

Last updated
September 19, 2022, 2:23 PM EDT

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

Locations

Country
Sweden
Region

Primary Investigator

Name
Joakim Semb
Affiliation
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2021-07-05
End date
2022-07-01
Keywords
Behavior
Additional Keywords
disjunction effect, dilemma, magical thinking
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In this study is a (qualitative) replication of the disjunction effect in the prisoners' dilemma (PD) documented by Shafir and Tversky (1992). In a between-subjects design, participants play a one-shot PD either in simultaneous-move form or as second-movers is a sequential PD. I test the null hypothesis that cooperation among simultaneous-movers is no higher than in the highest-cooperation group of second-movers (those facing either cooperation or rejection) against the one-sided alternative hypothesis that it is higher than in both of these groups, as was found by Shafir and Tversky (1992).
External Link(s)

Registration Citation

Citation
Semb, Joakim. 2022. "A replication of the disjunction effect in the prisoners' dilemma." AEA RCT Registry. September 19. https://doi.org/10.1257/rct.7917-1.1
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2021-07-05
Intervention End Date
2021-07-06

Primary Outcomes

Primary Outcomes (end points)
Cooperation rates in each of the three treatment groups (simultaneous-movers as well as second-movers facing cooperation and defection, respectively).
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
In a between-subjects design, participants play a one-shot prisoners' dilemma either in simultaneous-move form or as second-movers facing either cooperation or defection.
Experimental Design Details
Randomization Method
Computer randomization
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
520 participants
Sample size: planned number of observations
520 participants
Sample size (or number of clusters) by treatment arms
220 simultaneous-movers, 220 second-movers facing cooperation, 80 second-movers facing defection.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

shaftver.pdf

MD5: 39e76b2cb3c9aa068bb371f2f8546724

SHA1: 142496274fafab9bdf9a1b06717d6d93fc048737

Uploaded At: July 04, 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