Motivated beliefs and overconfidence in health insurance: a survey study with married individuals

Last registered on June 23, 2023

View Trial History

Pre-Trial

Trial Information

General Information

Title

Motivated beliefs and overconfidence in health insurance: a survey study with married individuals

RCT ID

AEARCTR-0011139

Initial registration date

May 08, 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

June 23, 2023, 3:38 PM EDT

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

Locations

Country

China

Region

Beijing

Primary Investigator

Name

Chang Zhang

Affiliation

the School of Economics, Peking University

Contact Primary Investigator

Other Primary Investigator(s)

PI Name

Ruo Jia

PI Affiliation

the School of Economics, Peking University

Contact Investigator

PI Name

Jiakun Zheng

PI Affiliation

the School of Finance, Renmin University of China

Contact Investigator

Additional Trial Information

Status

Completed

Start date

2023-05-09

End date

2023-05-22

Keywords

Behavior

Additional Keywords

Motivated beliefs, Overconfidence, Decisions between spouses, Insurance, Household finance

JEL code(s)

Secondary IDs

Prior work

This trial does not extend or rely on any prior RCTs.

Abstract

We conduct a survey-based experiment to examine health insurance demand and overconfidence in health among married individuals. The aim is to provide direct evidence that individuals are overconfident about their own and their spouse's health risks and that they believe they are healthier than their spouses. Additionally, we will investigate how individuals update health-related information about themselves compared to their spouses. The questionnaire comprises six parts. The first part is for collecting basic information about the subjects and their spouses, including age and gender. The second part focuses on the subjects' perceptions of their own and their spouses' health risk. The third part explores how they update health-related information about themselves and their spouses. The fourth part collects health information for both the subjects and their spouses. The fifth part collects information on the subjects' and their spouses' occupation, education level, lifestyle habits, risk preferences, and commercial insurance purchases. Finally, the sixth part focuses on the potential effect of the experimenter's demand. We expect that the results of the experiment will provide valuable insights into health insurance demand and overconfidence among married individuals, shedding light on how they update and perceive health-related information about themselves and their spouses.

External Link(s)

Registration Citation

Citation

Jia, Ruo, Chang Zhang and Jiakun Zheng. 2023. "Motivated beliefs and overconfidence in health insurance: a survey study with married individuals." AEA RCT Registry. June 23. https://doi.org/10.1257/rct.11139-1.0

Sponsors & Partners

Experimental Details

Interventions

Intervention(s)

We work on the following stages for both subjects and the spouses of the subjects.

In the first stage, we randomly selected 9 people at the subjects’ gender and age from previous surveys. And ask the subjects’, "Of the 10 people, including you, what do you think the chance is that your odds of getting cancer is higher than half of them (5 selected people)?"

In the second stage, we then present a piece of health-related news to the subjects. Recent studies published in top international oncology journals have shown that increasing physical activity can significantly lower the risk of developing many types of cancer. Specifically, engaging in at least 3 hours of moderate-intensity exercise per week has been shown to reduce the incidence of liver cancer by 27%, lung cancer by 26%, and breast cancer by 10%. Afterward, we asked subjects to choose one of the previously selected 9 people and informed them about how much that person exercises each week. We then asked for their perceived chance that their odds of getting cancer is higher than half of the 10 people again.

The updating order of self and spouse is randomized but consistent in the two stages.

Intervention Start Date

2023-05-09

Intervention End Date

2023-05-22

Primary Outcomes

Primary Outcomes (end points)

Perceived likelihood of hospitalization; Updates on perceived cancer risk

Primary Outcomes (explanation)

Updates on perceived cancer risk is the absolute difference in perceived cancer risk before and after the news was provided.

Secondary Outcomes

Secondary Outcomes (end points)

Secondary Outcomes (explanation)

Experimental Design

To compare the perceived health risks, we inquire about individuals' perceived likelihood of being hospitalized due to illness in the next year, in comparison to people of their age and gender, for both themselves and their spouses. We expect that on average, individuals believe that both themselves and their spouses are healthier than the general population with the same age and gender.

To compare perceived health risks, we also inquire about participants' perceived cancer risk and that of their spouses. Specifically, we ask about the likelihood that participants think they or their spouses are healthier than a half of selected people of their age and gender in terms of cancer risk. We anticipate that, on average, individuals will perceive themselves and their spouses to be healthier than a half of people in terms of cancer risk. We then demonstrate the high correlation between the two measures of overconfidence.

To compare individuals with their spouses, we ask participants, "Compared to your spouse, how likely do you think you are to be hospitalized due to illness in the next year?" We expect to find that, on average, individuals perceive themselves as healthier than their spouses.

To capture the information updating process, we present a piece of health-related news. Before and after sharing the news, we ask participants about their perceived chance that their and their spouses odds of getting cancer is higher than a half of the 10 people. We then compare the participants' response to the news when estimating their own and their spouses’ cancer risk.

Experimental Design Details

Randomization Method

All randomization is within subject, done by the computer.

Clarification on random assignment: This is a within-subjects design. That is, some subjects first update the information for themselves and others update the information of their spouses. The updating order of self and spouse is randomized by a computer.

Randomization Unit

Individual.

Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters

2000 married individuals.

Sample size: planned number of observations

4000 individuals, that is 2000 married individuals and their spouses.

Sample size (or number of clusters) by treatment arms

This is a within-subjects design and it has an information treatment.
Subjects will update information for both themselves (2000 individuals for control) and their spouses (2000 individuals for treatment).
We also compare subjects' beliefs before information treatment (for control) and after giving health-related information (for the treatment group).
For the good-bad news effect, about 1000 subjects receive good news for the control and 1000 subjects receive bad news for the treatment group.

Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Supporting Documents and Materials

IRB