A Field Intervention on the Willingness-to-Pay for Legal Fishing Nets at Lake Victoria

Last registered on October 07, 2021
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Pre-Trial

Trial Information

General Information

Title
A Field Intervention on the Willingness-to-Pay for Legal Fishing Nets at Lake Victoria
RCT ID
AEARCTR-0008335
Initial registration date
October 05, 2021

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
October 07, 2021, 4:28 PM EDT

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

Last updated
October 07, 2021, 4:42 PM EDT

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

Locations

Country
Tanzania, United Republic of
Region

Primary Investigator

Name
Florian Diekert
Affiliation
Heidelberg University
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Other Primary Investigator(s)

PI Name
Tillmann Eymess
PI Affiliation
Heidelberg University
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PI Name
Timo Goeschl
PI Affiliation
Heidelberg University
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PI Name
Santiago Gomez
PI Affiliation
Heidelberg University
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PI Name
Joseph Luomba
PI Affiliation
Tanzanian Fisheries Research Institute
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Additional Trial Information

Status
In development
Start date
2021-10-06
End date
2021-11-30
Keywords
Behavior, Environment & Energy, Firms & Productivity, Governance
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Natural resource systems like the artisanal fisheries at Lake Victoria in Tanzania are a prototypical example for the "tragedy of the commons": Each fisherman has an incentive to harvest more for his own short-term economic gain but the cost of doing so is borne by all.
To overcome such social dilemma and to ensure collectively sustainable fishing practices, rules and regulations are necessary. Among the measures to foster sustainable resource use at the Tanzanian lakeside is a governmental regulation that limits the mesh size of seine nets to 8mm. However, compliance with this regulation is weak and illegal nets (with mesh sizes smaller than 8mm) are common. Our first research objective is to estimate the baseline willingness to pay for legal fishing nets. To this end, we extend a multiple price list approach to fit a setup that allows the purchase of multiple units. Our second research objective is to test whether a "norm-nudge" can increase fishermen's willingness to pay for legal seine nets.
External Link(s)

Registration Citation

Citation
Diekert, Florian et al. 2021. "A Field Intervention on the Willingness-to-Pay for Legal Fishing Nets at Lake Victoria." AEA RCT Registry. October 07. https://doi.org/10.1257/rct.8335-1.1
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2021-10-06
Intervention End Date
2021-11-30

Primary Outcomes

Primary Outcomes (end points)
We estimate the number of net panels (0,1,2,3 or 4) demanded at seven prices, starting at 39,000 Tanzanian Shilling (TZS) for one net panel and continuing with steps of 6,000 TZS in ascending order with the last price at 75,000 TZS.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
We ask participants about their average catch, earnings, and number of trips at the workshop and in a follow-up survey to assess whether those that purchase 8mm nets change their production.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
There are two elements to the design: First, we elicit the willingness-to-pay (WTP) for a legal (8mm) net panel using a multi-unit multiple price list during workshops that are conducted at dagaa fish landing sites. Second, in half the landing sites, we provide a social-norm nudge, a verbal message to the participants before their WTP is elicited. The message provides information on the fact that fishermen in other workshops (at different landing sites) act in accordance with the desired behavior (adopting legal nets), without anchoring demand.
Experimental Design Details
Randomization Method
Randomization done in office by a computer.
Randomization Unit
Workshop
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
20 landing sites
Sample size: planned number of observations
400 order sheets (specifying number of units demanded at seven different prices), that is 20 participants per landing sites.
Sample size (or number of clusters) by treatment arms
10 landing sites as control, 10 landing sites with norm-nudge
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

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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