Perceived versus objective risk of a natural disaster

Last registered on January 19, 2024

Pre-Trial

Trial Information

General Information

Title
Perceived versus objective risk of a natural disaster
RCT ID
AEARCTR-0012544
Initial registration date
January 16, 2024

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
January 19, 2024, 2:13 PM EST

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

Locations

Region
Region
Region
Region

Primary Investigator

Affiliation
University of Bari Aldo Moro

Other Primary Investigator(s)

PI Affiliation
UCSD

Additional Trial Information

Status
In development
Start date
2024-03-31
End date
2024-05-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The earthquake hazard map of Italy has been examined by seismologists and volcanologists to identify areas with a comparable probability of a building collapse within the next 50 years. This probability is derived by multiplying the PGA (Peak Ground Acceleration) at an exceedance probability of 10% with the classic fragility curve. The estimated probability of collapse in the next 50 years in these locations is 10%. This objective probability will be compared with the perceived probability of the interviewees. All interviewees reside in a seismic area and share the same objective probability (10%) of experiencing a house collapse in the next 50 years.
The study aims to determine the between the objective risk and the perceived risk. It also seeks to compare the self-reported and other-reported likelihood of a house collapsing. We hypothesize that the probability reported for others is higher than the self-reported probability, whether those others are neighbors from the same city or citizens from another region's city [p(others) > p(self)]. This hypothesis suggests a form of optimism bias.

External Link(s)

Registration Citation

Citation
Gneezy, Uri and Anna Rinaldi. 2024. "Perceived versus objective risk of a natural disaster." AEA RCT Registry. January 19. https://doi.org/10.1257/rct.12544-1.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
Questionnaire administration among individuals from a randomized sample in four different Italian locations with buildings having the same objective probability of collapse. The questionnaire investigates:
- The perceived probability of the interviewee's house collapsing;
- The perceived probability of the collapse of the neighbour's house, as reported by the interviewee;
- The perceived probability of the collapse of a generic individual's house located in another city, as reported by the interviewee;
- Whether the interviewee intends to undertake any adaptation actions to prevent the collapse of their own building;
- If yes, which adaptation action;
- If yes, how much they are willing to pay.
Intervention Start Date
2024-04-30
Intervention End Date
2024-05-31

Primary Outcomes

Primary Outcomes (end points)
perceived probability, p
p(self)
p(other)

Primary Outcomes (explanation)
The perceived probability p is the self-reported probability.
P (self) is the perceived probability of interviewee's house collapsing within 50 years
P (other1) is the perceived probability of the collapse of the neighbour's house, as reported by the interviewee;
P (other2) is the perceived probability of the collapse of a generic individual's house located in another city, as reported by the interviewee.

Secondary Outcomes

Secondary Outcomes (end points)
Self-reported adaptation actions to prevent the collapse of her own building.
The budgeted expenditure to prevent the collapse of her own building.
Secondary Outcomes (explanation)
This outcome is crucial to understand if the interviewee is willing to implement an adaptation action to prevent the collapse of her house and if it aligns with the self-reported perceived probability.

Experimental Design

Experimental Design
The same questionnaire will be administered at the individual level in four different Italian locations where buildings have the same probability of collapse in the next 50 years.
Between-subjects and within-subjects comparison of risk perception for the risk of building collapse.
Incentives: If the respondent's perception matches the objective probability, which is the same for all scenarios (i.e., p=X%), they will receive a reward (10 euro Amazon voucher).
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
Randomization will occur at the individual level in each of the four locations where the study will be conducted.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
4 above mentioned Italian locations.
Sample size: planned number of observations
400 individuals residing in 4 different Italian locations. 100 individuals per location.
Sample size (or number of clusters) by treatment arms
100 citizens from Ischia, 100 citizens from Norcia.
100 citizens from Cosenza, 100 citizens from Lamezia Terme.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Behavioral Economics and Risk Laboratory Ethic Committee
IRB Approval Date
2023-12-21
IRB Approval Number
01/2023

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials