The impact of influencers in the willingness to pay for the protection of mangrove ecosystem services

Last registered on August 10, 2023


Trial Information

General Information

The impact of influencers in the willingness to pay for the protection of mangrove ecosystem services
Initial registration date
August 06, 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
August 10, 2023, 1:30 PM EDT

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


Primary Investigator

Universidade Nova de Lisboa - Nova SBE

Other Primary Investigator(s)

PI Affiliation
University College London, Institute for Risk and Disaster Reduction
PI Affiliation
Universidade Nova de Lisboa - Nova SBE

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Mangroves are invaluable ecosystems that offer a diverse range of benefits, including carbon sequestration, coastal protection, and providing habitats for various species. However, these ecosystems are under significant threat from human activities and require conservation efforts, particularly as coastal populations heavily rely on them for their livelihoods.

This study employs a randomized controlled trial (RCT) to investigate the potential impact of an influential singer's message on individuals' willingness to contribute for a conservation program of mangrove forests in a coastal area in the Sofala province, in Mozambique. The research design involves a control group exposed to a video highlighting general information about the benefits of mangroves. In contrast, the treatment group will be shown an additional video featuring a message from an influential singer emphasizing the crucial importance of conserving mangroves, and a call to action for everyone to be engaged. After watching the videos, participants will be asked to respond to a contingent valuation question, expressing their maximum willingness to pay or willingness to work for the conservation of mangrove forests in the study site.

This study aims to shed light on the effectiveness of using influential figures in promoting the conservation of natural resources. By exploring how targeted messages delivered through video interventions can shape individuals' environmental attitudes and willingness to contribute to conservation efforts, the findings will provide a deeper understanding of public behavior towards environmental preservation. Moreover, the results will have significant implications for designing effective communication strategies aimed at mobilizing public support and funding for the conservation of natural resources in Mozambique.
External Link(s)

Registration Citation

Leffers, Stefanus, Luisa Nobre and Margarida Ortigao. 2023. "The impact of influencers in the willingness to pay for the protection of mangrove ecosystem services." AEA RCT Registry. August 10.
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Experimental Details


This intervetion will show two different videos to the participants of the survey: one treatment and one control.
The control video will include general information on the benefits of mangroves, and the threats that are faced by this ecosystem. The participants of this video are someone from the scientif field, a resident from the local community that depends on mangrove for their livelihood and a local leader that is in charge of the conservation and restoring of this ecosystem.
Aditionally, the treatment video will include a message from a local influential person (a famous singer) who will send give the message of a call to action for protecting and restoring this ecosystem. The videos have the duration of approximately 3 minutes.

Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Measurements will include a set of questions in the survey, such as: Willingness to pay (WTP) for the conservation of mangrove forest in a specific area in the district of Beira; Trust in the people that appear in the video; The identified benefits of mangrove ecosystems; Perception on the threats to mangrove ecosystems; Worry regarding the future of mangrove ecosystems; Connection to mangrove forests
Primary Outcomes (explanation)
WTP in constructed using stated preferences methods, specifically a contingent valuation approach. Through a payment card, participants will be asked to assess their maximum ammount in Metical that they would be willing to pay for a mangrove conservation program that would be held in the study site, or the maximum hours of work they would be willing to put on this same conservation program. "Connection to mangrove forests" will be constructed through a set of 5 questions with a 5-point likert scale related to how people perceive the importance of mangrove forests to their daily lives, to their community, etc.

Secondary Outcomes

Secondary Outcomes (end points)
Other outcomes, also included in the survey include: Belief in the efficiency of the conservation program that is to be held; belied that other people would also participate in this program; perception on the importance of participating in a conservation program; agreement that the local community should participate in a mangrove conservation program
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The 1000 participants of the survey will be divided into 2 groups: treatment and control. The control group will be shown the video with the general information on mangrove forests’ benefits, threats, and what need to be done for a sustainable management. The treatment group video will include the same video, and additionally a statement from a famous singer, calling for action on the conservation of mangroves.
Experimental Design Details
Randomization Method
Randomization will be done with the survey platform, in the beggining of the interview.
Randomization Unit
Individual level
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
No clusters
Sample size: planned number of observations
1000 individuals
Sample size (or number of clusters) by treatment arms
500 individual in the treatment groups, 500 individuals in the control group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Nova School of Business and Economics - Universidade Nova de Lisboa
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials