Measuring Rationality under Mental Illness

Last registered on September 04, 2023


Trial Information

General Information

Measuring Rationality under Mental Illness
Initial registration date
August 31, 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, 6:50 AM EDT

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


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Primary Investigator

Jinan University

Other Primary Investigator(s)

PI Affiliation
Shanghai International Studies University
PI Affiliation
National University of Singapore and Hong Kong University of Science and Technology

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The aim of this project is to investigate economic preferences and rationality among individuals diagnosed with psychiatric disorders. We will use two widely recognized experimental paradigms in the literature, namely social decision-making (eg., Fisman et al., 2007) and risk decision-making tasks (eg., Choi et al., 2007), to evaluate the decision-making abilities of psychiatric patients. The study will recruit individuals diagnosed with several common types of psychiatric disorders according to ICD-10 diagnostic criteria, along with demographically-matched normal controls. By taking an interdisciplinary approach, we hope to identify potential decision deficits among the patients, as well as commonalities and differences among individuals diagnosed with different types of psychiatric disorders, shedding light on the underlying mechanisms of psychiatric diseases. Ultimately, this research will not only advance our understanding of mental disorders but also provide new insights into the heterogeneity of economic preferences and rationality among human behaviors. The experiment will be conducted only if we obtain consent from the patient (consent from the patient's family is required for those without full capacity). The data will be collected from clinical inpatients and outpatients.
External Link(s)

Registration Citation

Sheng, Qiang, Shuangyu Yang and Songfa Zhong. 2023. "Measuring Rationality under Mental Illness." AEA RCT Registry. September 04.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Rationality based on revealed preference toolkit, risk/social preference, and types of mental illness.
Primary Outcomes (explanation)
The experiments are based on a budget-line design from revealed preference literature. We aim to link the rationality based on revealed preference analysis in social/risk tasks with different types of mental illness.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
For the main experiment, there are two parts. We want to elicit subjects’ risk preference and their social preference in standard risk and social tasks. Each of the mentioned tasks is taken from well-established experimental designs.

Part 1: Subjects are presented with 22 standard budgetary choices, each with two Arrow securities, to measure their risk preference and rationality. This experimental design was first introduced by Choi et al. (2007) and used in many previous studies in revealed preference analysis. In our experiment, to help subjects understand, we present a discrete choice set consisting of 11 options from the original full budget line as per Kim et al. (2018).

Part 2: Subjects will be presented with 22 social preference elicitation tasks in a modified dictator game style (Fisman et al., 2007). This method is among the more popular ones for eliciting social attitudes.

Upon signing the consent form, participants in both experimental tasks will receive detailed instructions about the experiment. To ensure their full understanding of the experiment, two practice trials will be administered before the actual experiment starts. Additionally, participants are required to answer a set of test questions correctly before starting the experiment.

Part 3: Post-experiment questionnaires will include risk and social preference items adapted from Global Preference Survey (Falk et al., 2018), as well as the 10-item version of the Big Five personality scale.

Part 4: Partial sets of Raven IQ.

Part 5: Clinical scale scores for each patient are evaluated by a qualified physician based on the specific type of diagnosed mental disorder.
Experimental Design Details
Not available
Randomization Method
The randomization is performed by a built-in computer algorithm during the experiment process.
Randomization Unit
Experimental sessions of different types of tasks (the order of social/risk task sessions, i.e., part 1 and part 2);
Experimental tasks (the order of tasks within each session).
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
2 groups (decision makers with/without clinically diagnosed mental illness).
Sample size: planned number of observations
1000 individuals.
Sample size (or number of clusters) by treatment arms
600 decision makers with clinic mental illness (150-200 individuals for each type of illness);
400 general decision makers without clinic mental illness.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethics Committee of the Seventh People's Hospital in Hangzhou, Zhejiang province
IRB Approval Date
IRB Approval Number