Apologies in Public Goods Game
Last registered on January 15, 2019

Pre-Trial

Trial Information
General Information
Title
Apologies in Public Goods Game
RCT ID
AEARCTR-0003567
Initial registration date
November 15, 2018
Last updated
January 15, 2019 5:05 AM EST
Location(s)

This section is unavailable to the public. Use the button below to request access to this information.

Request Information
Primary Investigator
Affiliation
University of Warwick
Other Primary Investigator(s)
PI Affiliation
University of Warwick
Additional Trial Information
Status
On going
Start date
2018-11-01
End date
2020-11-01
Secondary IDs
Abstract
The project aims to examine the effect of apologies on coordination and cooperation, the underlying mechanism and its efficiency, in a public
goods experimental game.
External Link(s)
Registration Citation
Citation
Yeo, Jonathan and SHI ZHUO. 2019. "Apologies in Public Goods Game." AEA RCT Registry. January 15. https://www.socialscienceregistry.org/trials/3567/history/40209
Experimental Details
Interventions
Intervention(s)
Intervention Start Date
2018-11-01
Intervention End Date
2020-11-01
Primary Outcomes
Primary Outcomes (end points)
Average group contribution in treatment groups compared to control groups;
Dynamics of individual apologies and contribution in treatment and control groups;
Dynamics of individual estimation of other group members' contribution and evaluation of other group members' altruism in treatment and control groups
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Individual characteristics and correlation with primary outcomes;
Individual contribution preference in one-shot public goods games and correlation with primary outcomes
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
An experimental lab setting will be used for the research. At the beginning of the session, each participant will be randomly assigned to 1 of the 3 treatments: control, public apologies, private apologies. Participants will be randomly assigned to groups of 4 and play a standard repeated public goods game for 16 periods. In the treatment groups, participants will be able to send apology messages to group members after contributions revealed. We also plan to conduct three extra treatments with regrouping in each period to further explore the mechanism.
Experimental Design Details
Not available
Randomization Method
All randomizations are done via the python-based otree computer program.
Randomization Unit
Individual
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
312 to 432 participants
Sample size: planned number of observations
312 to 432 participants
Sample size (or number of clusters) by treatment arms
52 to 72 control (13 to 18 groups), 52 to 72 public apologies (13 to 18 groups), 52 to 72 private apologies (13 to 18 groups),
52 to 72 control with regrouping (13 to 18 groups), 52 to 72 public apologies with regrouping (13 to 18 groups), 52-72 private apologies with regrouping(13 to 18 groups)
For regrouping treatments, we might do 24 to 40 for both private and public apologies instead, or just do one of the two apologies, depending on the available funding.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The closest reference we can find for our main outcome - effect of apologies on contribution in public goods game - is the following paper. Reference: Haruvy, E., Li, S. X., McCabe, K., & Twieg, P. (2017). Communication and visibility in public goods provision. Games and Economic Behavior, 105, 276-296.; Effect size=(M2 - M1) /√((SD1^2 + SD2^2) ⁄ 2); MPCR=0.3: (76.8-6.7)/√((31.3^2 + 12.7^2) ⁄ 2)=2.08 SD; MPCR=0.75: (96.5-13.9)/√((6^2 + 18.6^2) ⁄ 2)=4.23 SD; MPCR in our public goods game=0.5, so we take the average of their effect sizes = 3.15 SD; Since our game is different from the game used in the paper and more abstract, our expected effect size might be much lower than that. We use effect size of 1 SD for power calculation. With an effect size of 1 SD, a sample size of >35 is sufficient to obtain power of 0.8 and alpha=0.05
Supporting Documents and Materials

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
University of Warwick Economics Departmental Ethical Approval officer
IRB Approval Date
2018-10-25
IRB Approval Number
N/A
Analysis Plan

There are documents in this trial unavailable to the public. Use the button below to request access to this information.

Request Information