A Dictator Game Experiment with Face Mask Wearers and Non-mask Wearers in Japan

Last registered on May 31, 2024

Pre-Trial

Trial Information

General Information

Title
A Dictator Game Experiment with Face Mask Wearers and Non-mask Wearers in Japan
RCT ID
AEARCTR-0012025
Initial registration date
September 03, 2023

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 04, 2023, 7:01 AM EDT

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

Last updated
May 31, 2024, 4:54 AM EDT

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

Locations

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

Request Information

Primary Investigator

Affiliation
Osaka University

Other Primary Investigator(s)

PI Affiliation
Kwansei Gakuin University
PI Affiliation
The University of Tokyo

Additional Trial Information

Status
On going
Start date
2023-09-01
End date
2026-03-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In this study, we conduct a dictator game experiment with face mask wearers and non-mask wearers in Japan, and ascertain allocation tendencies between two anonymous individuals, between two mask wearers or two non-mask wearers, and between a mask wearer and a non-mask wearer. By so doing, we assess “ingroup-favoritism,” “ingroup bias,” and “outgroup bias” of the mask wearers and non-mask wearers, respectively. Here, ingroup-favoritism is defined as the difference between the money amounts allocated in the dictator game experiment to an individual of the same group (i.e., a recipient who wears a mask for the mask wearers and a recipient who does not wear a mask for the non-mask wearers) and to an individual of the different group (i.e., a recipient who does not wear a mask for the mask wearers and a recipient who wears a mask for the non-mask wearers). Also, ingroup bias is defined as the difference between the money amounts allocated to an individual of the same group as the allocator and to an anonymous individual, while outgroup bias is defined as the difference between the money amounts allocated to an individual of a different group from the allocator’s and to an anonymous one. We also examine whether the biases depend on the recipient’s nationality or not.
External Link(s)

Registration Citation

Citation
Sasaki, Shusaku, Hirofumi Kurokawa and Taisuke Nakata. 2024. "A Dictator Game Experiment with Face Mask Wearers and Non-mask Wearers in Japan." AEA RCT Registry. May 31. https://doi.org/10.1257/rct.12025-3.0
Experimental Details

Interventions

Intervention(s)
We set the following seven treatment conditions in the dictator game experiment:

A) Anonymous: A recipient is anonymous for an allocator.
B) Japanese mask wearers: A recipient wears a mask. The recipient nationality is Japanese.
C) Japanese non-mask wearers: A recipient does not wear a mask. The recipient nationality is Japanese.
D) East Asian mask wearers: A recipient wears a mask. The recipient nationality is non-Japanese and East Asian.
E) East Asian non-mask wearers: A recipient does not wear a mask. The recipient nationality is non-Japanese and East Asian.
F) Non-East Asian mask wearers: A recipient wears a mask. The recipient nationality is non-Japanese and non-East Asian.
G) Non-East Asian non-mask wearers: A recipient does not wear a mask. The recipient nationality is non-Japanese and non-East Asian.
Intervention Start Date
2023-09-08
Intervention End Date
2023-09-15

Primary Outcomes

Primary Outcomes (end points)
Allocation in the dictator game experiment (More specifically, within-difference between the allocated amounts in the second dictator game and the first anonymous dictator game. Please see the details in the pre-analysis plan.)
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Attitudes toward the COVID-19-related policies (Agree or disagree for the policy of easing restrictions related to infectious disease control)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct dictator game experiments in the following seven conditions:

A) Anonymous: A recipient is anonymous for an allocator.
B) Japanese mask wearers: A recipient wears a mask. The recipient nationality is Japanese.
C) Japanese non-mask wearers: A recipient does not wear a mask. The recipient nationality is Japanese.
D) East Asian mask wearers: A recipient wears a mask. The recipient nationality is non-Japanese and East Asian.
E) East Asian non-mask wearers: A recipient does not wear a mask. The recipient nationality is non-Japanese and East Asian.
F) Non-East Asian mask wearers: A recipient wears a mask. The recipient nationality is non-Japanese and non-East Asian.
G) Non-East Asian non-mask wearers: A recipient does not wear a mask. The recipient nationality is non-Japanese and non-East Asian.

Each participant in the five dictator game experiments as an allocator. We randomly set the order of the above conditions to create seven groups in each of the mask wearers and non-mask wearers samples. The order of five dictator games as follows:

Group 1. A⇒A⇒A⇒A⇒A
Group 2. A⇒B⇒C⇒F⇒G
Group 3. A⇒C⇒B⇒E⇒D
Group 4. A⇒D⇒E⇒B⇒C
Group 5. A⇒E⇒D⇒C⇒B
Group 6. A⇒F⇒G⇒B⇒C
Group 7. A⇒G⇒F⇒C⇒B

First, we set up six groups: the Japanese condition (B and C), the East Asian condition (D and E) and the Non-East Asian condition (F and G). In all groups, the first among the five games is played in the anonymous condition (A). In the second and third games, for each nationality condition, we randomly set either the in-group condition (B, D and F) or the out-group condition (C, E and G). In Groups 2 and 3, the fourth and fifth games will be played in the East Asian or Non-East Asian condition. In Groups 4, 5, 6 and 7, the fourth and fifth games are played in the Japanese condition. The order of the in-group and out-group conditions is set to correspond to the order of the in-group and out-group conditions in the second and third games. Consequently, each of the mask wearing and non-wearing samples have six groups. Furthermore, we create Group 1 as a control group, where we present the anonymous condition (A) five times, to address potential order effects caused by successive participation in the dictator games. Totally, each of the mask wearing and non-wearing samples have seven groups, including the control group.

We conduct the between-analysis to test the existence of ingroup favoritism, ingroup bias, and outgroup bias in each of face mask wearers and non-mask wearers. We also investigate whether the mask wearers’ ingroup favoritism change between when the nationality of the recipient pair is Japanese and when the nationality of the recipient pair is non-Japanese. Our experimental design allows for both between- and within-individual comparisons. We further conduct the within-analysis to check the robustness of the between-analysis.

We explain more details in the attachment of the pre-analysis plan.
Experimental Design Details
Not available
Randomization Method
Stratified randomization by a survey company. The strata are based on sex, age, and region.
Randomization Unit
Individuals
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
N/A
Sample size: planned number of observations
3,360 individuals (1,680 mask wearers and 1,680 non-mask wearers)
Sample size (or number of clusters) by treatment arms
1,680 mask wearers include seven treatment groups (6*240 mask wearers = 1440 mask wearers) and one control group (240 mask wearers).

Similarly, 1,680 non-mask wearers include seven treatment groups (6*240 non-mask wearers = 1440 non-mask wearers) and one control group (240 non-mask wearers).
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
In the meta-analysis (Balliet et al., 2014), d of the ingroup-favoritism is 0.32. When we calculate the necessary sample size under the condition of power=0.8 and alpha=0.05, it becomes 155 for each group. To test multiple hypotheses, we finally set a sample size of 240 participants per group, which is the largest size as far as our budget goes. Reference: Balliet, D., Wu, J., & De Dreu, C. K. (2014). Ingroup favoritism in cooperation: a meta-analysis. Psychological bulletin, 140(6), 1556.
IRB

Institutional Review Boards (IRBs)

IRB Name
The University of Tokyo IRB
IRB Approval Date
2023-08-22
IRB Approval Number
23-237
IRB Name
Center for Infectious Disease Education and Research, Osaka University IRB
IRB Approval Date
2023-08-22
IRB Approval Number
2023CRER0822-2
Analysis Plan

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

Request Information