Estimating Demand When Turning a Public Bad into an Impure Public Good

Last registered on June 18, 2024
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Pre-Trial

Trial Information

General Information

Title
Estimating Demand When Turning a Public Bad into an Impure Public Good
RCT ID
AEARCTR-0011195
Initial registration date
May 01, 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
May 03, 2023, 4:35 PM EDT

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

Last updated
June 18, 2024, 11:57 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country
Senegal
Region

Primary Investigator

Name
Molly Doruska
Affiliation
Cornell University
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Other Primary Investigator(s)

PI Name
Christopher Barrett
PI Affiliation
Cornell University
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PI Name
Jason Rohr
PI Affiliation
Notre Dame University
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PI Name
Samba Mbaye
PI Affiliation
Universite Gaston Berger
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Additional Trial Information

Status
Completed
Start date
2023-05-29
End date
2023-12-31
Keywords
Agriculture, Health
Additional Keywords
Schistosomiasis
JEL code(s)
O13, H41, I15
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Aquatic vegetation is a public bad that grows in common property freshwater resources and provides the habitat for snails that host schistosomes that infect, and reinfect, rural villagers in our northern Senegal study sites. We will estimate demand for compost and animal feed made from aquatic vegetation in northern Senegal, with and without information about the production method's public good benefit in controlling the infectious disease schistosomiasis. Our objective is to quantify individuals' willingness to pay (WTP) for as-yet-nonmarketed impure public goods that bundle a public good - reduced infectious disease exposure - with a private good - in this case, the agricultural inputs compost and livestock feed - and to unpack these distinct sources of valuation of each good.
External Link(s)

Registration Citation

Citation
Doruska, Molly et al. 2024. "Estimating Demand When Turning a Public Bad into an Impure Public Good." AEA RCT Registry. June 18. https://doi.org/10.1257/rct.11195-3.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
We will use a generalized second price auction to estimate demand curves for two impure public goods, compost and animal feed produced using AVR. We will vary the information provided to participants at the time of the auction.
Intervention (Hidden)
We will use a generalized second price auction to estimate demand curves for two impure public goods, compost and animal feed produced using AVR. We will vary the information provided to participants at the time of the auction. In treatment arm, households will be told of the private productivity gains of using compost and the potential cost savings from animal feed. In another treatment arm they will also be told of the additional benefit of reduced schistosomiasis exposure from AVR. We use this experimental design to the hypothesis that households' valuation of these agricultural inputs, the impure public goods, partly incorporate their valuation of reduced disease exposure.

To disentangle the two sources of value for compost and animal feed produced from removed aquatic vegetation, we will assign each participant to one of two information treatment arms:
1. Private productivity gains information
All participants receive information about the private benefits of using compost and animal feed from AVR. Material will be based on estimates from Rohr et al. (2022) and will be developed with the team directly involved in the production of compost and animal feed for Rohr et al. (2022). The same team, SIA, will produce compost and animal feed using the procedure developed in Rohr et al. (2022) to match the characteristics of the compost and animal feed as best as possible. All information treatments will be reviewed by local partners and presented in a culturally appropriate way.
2. Public health impacts information
Participants assigned to the public information treatment will receive all of the information in the private information treatment arm. In addition, participants will receive information about the public benefits of AVR to reduce schistosomiasis exposure, explaining that the compost and feed are co-products along with infectious disease control. Material will be based on estimates from Rohr et al. (2022) and will be developed with the teams directly involved in Rohr et al. (2022). Information will focus on reduced schistosomiasis transmission as estimated by Rohr et al. (2022). All information treatments will be reviewed by local partners and presented in a culturally appropriate way.
Intervention Start Date
2023-05-29
Intervention End Date
2023-06-23

Primary Outcomes

Primary Outcomes (end points)
Willingness to pay for compost and animal feed
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
A generalized second price auction will elicit each participant’s WTP for compost and animal feed. We will randomly assign participants to an auction with our without additional information about the compost and animal feed.
Experimental Design Details
Randomization Method
Stratified randomization done in office by a computer
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
20 villages
Sample size: planned number of observations
800 people
Sample size (or number of clusters) by treatment arms
20 villages, 4 auctions in each village, 10 people per auction, 2 auctions per each treatment arm in each village, so 400 people per treatment arm
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Assuming a standard deviation of 100 FCFA, 0.05 significance, and 80% power, we estimate a detectable effect of just under 50 FCFA (less than $0.10 USD) between the two auction treatment arms with at leat seven participants in each auction.
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Cornell University Institutional Review Board for Human Participants
IRB Approval Date
2023-04-12
IRB Approval Number
IRB0010544 (2109010544)
Analysis Plan

Analysis Plan Documents

Estimating Demand When Turning a Public Bad into an Impure Public Good

MD5: 0062eaacc8d58c75430414e0e2c90aa5

SHA1: 0016ef6c33023fbf9753f185d1ed37ccbd2dd2e7

Uploaded At: May 29, 2023

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
June 30, 2023, 12:00 +00:00
Data Collection Complete
Yes
Data Collection Completion Date
June 30, 2023, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
20 villages
Was attrition correlated with treatment status?
No
Final Sample Size: Total Number of Observations
712 individuals
Final Sample Size (or Number of Clusters) by Treatment Arms
40 control, 40 treatment
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials