Belief Updating, Risk Information, and Urban Flooding: A Field Experiment in Mozambique

Last registered on December 22, 2021

Pre-Trial

Trial Information

General Information

Title
Belief Updating, Risk Information, and Urban Flooding: A Field Experiment in Mozambique
RCT ID
AEARCTR-0008451
Initial registration date
October 27, 2021
Last updated
December 22, 2021, 9:23 AM EST

Locations

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Primary Investigator

Affiliation
Nova SBE

Other Primary Investigator(s)

Additional Trial Information

Status
On going
Start date
2021-07-30
End date
2022-09-30
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study investigates belief updating in the context of flood risk in Mozambique. Accurate forecasts and risk information do not always bring about the desired preparedness actions from communities at risk. I develop and test experimentally two video interventions to increase flooding related awareness, worry and preparedness of urban households. The video interventions contain the same information about flood risk, causes, effects, and guidance on preparation, but they differ in the actors conveying the message. While the first video features public officials, in the second video local residents with recent flooding experience present the information by drawing on their own experiences.
External Link(s)

Registration Citation

Citation
Leeffers, Stefan. 2021. "Belief Updating, Risk Information, and Urban Flooding: A Field Experiment in Mozambique." AEA RCT Registry. December 22. https://doi.org/10.1257/rct.8451-2.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
I analyze the impact of two interventions disseminating information through 6-minute videos, a public official video and a experience-based video. The videos are incorporated into questionnaires with the target population and take place from September to November, 2021. The goal of the interventions is to increase the flood risk awareness, worry and preparedness of the participants. The video interventions contain the same information about flood risk, causes, effects, and guidance on preparation. The visuals in the videos alternate between the speakers and (moving) images that help transmit the message. Publicly available images and recordings of local news outlets are used for this purpose. The same visuals are used in both interventions. To promote inclusiveness among all ages and education levels, the standard Portuguese versions of the videos are also dubbed in Chuabo, the main local language. In the public official intervention (treatment 1 or T1) the information is delivered by local government officials (one man and one woman) responsible for disaster risk management. The experience-based intervention (treatment 2 or T2) features two local residents (one man and one woman). The latter actors draw on their recent flooding experience to deliver the information. Finally, to measure the effectiveness of the interventions, I created a placebo video (control or C). This 6-minute video contains general information about the city of Quelimane, its history and main economic activities. The information is delivered by local residents, contains (moving) images, and is also made available in Chuabo.
Intervention Start Date
2021-09-16
Intervention End Date
2021-11-24

Primary Outcomes

Primary Outcomes (end points)
Measurements include multiple sources of data: survey questions and behavioral measures based on SMS technology. The in-depth household survey questionnaire is divided into four parts. The first part includes detailed questions about the household’s composition, economic status, access to public services and financial instruments, flooding experience and trust. The second part is the video and the third part includes detailed questions about risk awareness, worry, preparedness, risk and time preferences. The final part of the questionnaire is the behavioral experiment.

The chief survey questionnaire excludes the first part, since the necessary context variables such as demographic characteristics and flooding experience are collected during a mapping exercise that precedes these surveys. The chief survey questions mostly differ from the household survey since they are focused on the block in general, not necessarily the chief’s household. Nonetheless, the same topics are covered.

The short survey includes questions from across most in-depth household survey sections. Some questions are asked before and others after showing the video. Additionally, it includes questions to determine the respondent's exposure to spillovers.

The survey measures are supplemented with a behavioral measures through SMS. After the survey, the respondents receive two different invitations through text messages. The first invitation, offers some useful information about the cyclone warning system currently active in Quelimane. Respondents have to reply ‘yes’ to receive the information. The second invitation asks respondents to send anonymous feedback and suggestions about disaster risk management to the local government.

The primary outcomes are survey questions on 1) risk awareness, 2) risk worry and 3) preparation intention, and the behavioral measure through SMS.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
An important secondary outcome is the behavioral experiment. An insurance game is played to test the hypothesis that past experiences influence preparation behavior.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment has three phases.

First, a mapping exercise is conducted for which all city blocks of Quelimane are visited. During these visits the block limits are established and interviews are conducted with the block chiefs.

Second, the intervention takes place during the in-depth chief and household interviews in 300 city blocks.

Third, the intervention takes place during short interviews with 30 percent of the households in 150 city blocks (subset of original sample).
Experimental Design Details
Not available
Randomization Method
The city blocks were randomly allocated into the control and two treatment groups stratified by neighborhood using Stata.
Randomization Unit
City blocks
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
300 city blocks
Sample size: planned number of observations
300 city block chiefs, 600 in-depth interviews with household head or spouse and 3562 short interviews with household head or spouse
Sample size (or number of clusters) by treatment arms
100 city blocks per treatment arm for the in-depth interviews and 50 city blocks per treatment arm for the short interviews.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
The Scientific Council of Nova School of Business and Economics
IRB Approval Date
2021-02-24
IRB Approval Number
N/A