Ambiguity attitudes for natural and artificial sources and real behaviors under ambiguity

Last registered on July 08, 2022


Trial Information

General Information

Ambiguity attitudes for natural and artificial sources and real behaviors under ambiguity
Initial registration date
July 06, 2022

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 08, 2022, 9:50 AM EDT

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



Primary Investigator

Ryukoku University

Other Primary Investigator(s)

PI Affiliation
Kyoto University

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
We compare ambiguity attitudes for natural and artificial sources in both gain and loss domains. In addition, we compare the relationships between the ambiguity attitudes and real behaviors under ambiguity (preventive health and disaster preparedness behaviors) for the natural source with those for the artificial source; this is also examined in both gain and loss domains. Furthermore, we examine heterogeneity in ambiguity attitudes and in the relationship between ambiguity attitudes and real behaviors under ambiguity.
External Link(s)

Registration Citation

Fujimi, Toshio and Masahide Watanabe. 2022. "Ambiguity attitudes for natural and artificial sources and real behaviors under ambiguity." AEA RCT Registry. July 08.
Experimental Details


We conduct four different treatments in 2×2 between-subjects design, namely, artificial source in gain domain, artificial source in loss domain, natural source in gain domain, and natural source in loss domain. We measure ambiguity attitudes for the various sources and outcome domains.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Ambiguity attitudes (ambiguity insensitivity index and ambiguity aversion index)
Primary Outcomes (explanation)
Preventive health behaviors
Disaster preparedness behaviors
Risk preference
Time preference
Cognitive reflection test
Investment behavior
Demographic Variables (age, gender, income, educational background, health condition, natural hazard experience)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct a web survey using a panel owned by an Internet-based research company in Japan. From among the registered members, we limit our survey to the people living in Osaka. The survey company randomly requests responses from registrants and accepts them on a first-come, first-served basis. Before answering the survey, the respondents are informed that the survey will take 20 to 30 minutes to complete.

The web survey is conducted in three parts. The first part involves a practice of answering matching probability. The second part involves experiments to obtain matching probabilities. The third part focuses on the subjects’ demographic variables, risk preference, time preference, and preventive health and disaster preparedness behaviors and conducts cognitive tests.

To elicit ambiguity attitudes, we apply the methods of Baillon et al. (2018) and Dimmock et al. (2016) for natural and artificial sources, respectively. In the natural source experiments, respondents are asked to choose between an ambiguous and an unambiguous option. In the artificial source experiments, respondents are required to choose between ambiguous lottery and unambiguous (risk) lottery.

We elicit ambiguity attitudes for different sources and outcome domains: 1) natural source in gain domain; 2) natural source in loss domain; 3) artificial source in gain domain; and 4) artificial source in loss domain. We randomly assign four different treatments for the respondents.

Baillon, A., Huang, Z., Selim, A., & Wakker, P. P. (2018). Measuring ambiguity attitudes for all (natural) events. Econometrica, 86(5), 1839-1858.
Dimmock, S. G., Kouwenberg, R., & Wakker, P. P. (2016). Ambiguity attitudes in a large representative sample. Management Science, 62(5), 1363-1380.
Experimental Design Details
Randomization Method
Randomization done in office by a computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
800 individuals
Sample size: planned number of observations
800 individuals
Sample size (or number of clusters) by treatment arms
200 individuals per arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Institutional Review Board, Ryukoku University
IRB Approval Date
IRB Approval Number


Post Trial Information

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials