Willingness to pay for Infection and Treatment Method vaccine against East Coast Fever using Becker Degroot Marshack mechanism

Last registered on December 20, 2024
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Pre-Trial

Trial Information

General Information

Title
Willingness to pay for Infection and Treatment Method vaccine against East Coast Fever using Becker Degroot Marshack mechanism
RCT ID
AEARCTR-0014984
Initial registration date
December 13, 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
December 20, 2024, 11:36 AM EST

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

Locations

Country
Kenya
Region
Narok county

Primary Investigator

Name
Aditi Surve
Affiliation
Washington State University
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Shanthi Manian
PI Affiliation
PI Name
Isabelle Cohen
PI Affiliation

Additional Trial Information

Status
In development
Start date
2025-01-20
End date
2025-05-31
Keywords
Agriculture, Behavior
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Quantifying the willingness to pay (WTP) for new technologies is essential for accurately estimating demand. The Becker-DeGroot-Marshack (BDM) method is a well-established revealed-preference approach for assessing individuals' WTP for public goods and services. BDM is extensively used in experimental economics, and recent applications have extended to estimating demand in developing countries. However, existing studies often overlook variations in budget constraints over time, potentially leading to biased estimations. This study addresses this gap by employing the BDM mechanism to assess the willingness to pay for a new vaccine for East Coast Fever (ECF) among cattle farmers in Kenya. ECF is a significant threat to livestock populations in Africa, particularly cattle. Using random variation in timing, we also seek to assess the impact of exogenous liquidity constraints on WTP elicitation. If WTP represents a stable valuation, independent of constraints, then recent shocks and other constraints should not affect measured WTP. If they do, that would suggest that what we capture as willingness-to-pay may truly represent some combination of willingness and ability to pay. Our study will also contribute to a broader literature on optimal pricing strategies for vaccine adoption and barriers to vaccination use.
External Link(s)

Registration Citation

Citation
Cohen, Isabelle, Shanthi Manian and Aditi Surve. 2024. "Willingness to pay for Infection and Treatment Method vaccine against East Coast Fever using Becker Degroot Marshack mechanism ." AEA RCT Registry. December 20. https://doi.org/10.1257/rct.14984-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2025-01-20
Intervention End Date
2025-05-31

Primary Outcomes

Primary Outcomes (end points)
Maximum willingness to pay for the number of calves chosen to vaccinate
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment's sample consists of households engaging in livestock management activities in Narok County, Kenya. Households that refuse to participate will be excluded from the experiment. We target 774 households, who will be randomly assigned to different weeks of the survey.

This study will take place in Narok County, Kenya, from January 2025 to May 2025. Participants will be surveyed by enumerators, including detailed data on recent expenses. The survey will be programmed via Commcare and conducted on a tablet. The BDM exercise will take place after the survey; during it, participants will be able to purchase the ITM vaccine at a (potentially) subsidized rate.

For the exercise, participants will first state the number of calves they want to vaccinate. Participants will then state their maximum WTP for vaccinating the chosen number of calves. A random price will then be drawn from a predefined distribution. If this random price is less than or equal to the participant's WTP, they will purchase the vaccine at the drawn price. If the random price is higher, they cannot buy the product through the survey.

The data collection process will involve randomizing the order in which participants will be surveyed. Specifically, each participant will be randomized to receive the survey and WTP elicitation in a pre-specified week during the survey period (January 2025 to May 2025). This randomization is expected to introduce exogenous variation in liquidity constraints based on seasonality and the randomness of recent events.

Participants who successfully purchase the vaccine through the WTP exercise will have 48 hours to gather/raise funds. They will be notified of the potential vaccination opportunity one week in advance of their randomly assigned survey week. This notification is to enable households to gather funds before the visit, mimicking the typical purchase environment for the vaccine.
Experimental Design Details
Randomization Method
Households' survey timing will be randomly assigned to different weeks. The researchers will randomize these assignments using a computer.
Randomization Unit
Household
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
774 Households
Sample size: planned number of observations
774 Households
Sample size (or number of clusters) by treatment arms
50 surveys per week
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
KEMRI Scientific Ethics Review Unit
IRB Approval Date
2023-03-31
IRB Approval Number
KEMRI/SERU/CPHR/027/4314
Analysis Plan

Analysis Plan Documents

Pre Analysis Plan Summary

MD5: 6dabd8d700bc9e9a703dc39fb936d68f

SHA1: defc89f787db47f118eb2056e66d04567b917a69

Uploaded At: December 13, 2024

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