Co-producing environmental conservation and social equity: Is conditionality in Payments for Ecosystem Services a necessity or impediment?

Last registered on December 20, 2021


Trial Information

General Information

Co-producing environmental conservation and social equity: Is conditionality in Payments for Ecosystem Services a necessity or impediment?
Initial registration date
September 23, 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
September 28, 2021, 3:30 PM EDT

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

Last updated
December 20, 2021, 8:12 AM EST

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


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Primary Investigator

Purdue University

Other Primary Investigator(s)

PI Affiliation
Purdue University
PI Affiliation
Brandeis University
PI Affiliation
Purdue University
PI Affiliation
Utah State University

Additional Trial Information

On going
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Modern conservation approaches have proved largely ineffective to redress ecosystem degradation at local to global scales. There is a growing interest in market-based conservation as a promising alternative. In particular, payments for ecosystem services (PES) have become increasingly popular, with $66 billion spent globally on watershed-focused PES programs as of 2011. At the core of PES is the assumption that payments made to natural resource managers to produce environmental benefits must be conditional on observable actions or measurable outcomes, which implies that natural resource managers need to be coerced (through monitoring and enforcement) to conserve the environment. However, cultural and political ecologists have long argued that natural resource managers in the Global South possess intrinsic motivations for conservation and that social and cultural systems, political economies, and institutions play important roles in shaping their natural resource decisions. Evidence from geography and other social sciences also suggests that enforcing conditionality in PES is associated with reduced social equity within and across communities. The goal of this research is to determine the role of conditionality in PES in shaping human-environment relations, and the extent to which conditionality can be removed to produce environmental benefits without sacrificing social equity. The research objectives are to: (1) determine the effect of conditionality in PES on environmental conservation outcomes; (2) determine the effect of conditionality in PES on social equity outcomes; and (3) identify mechanisms through which conditional and unconditional payments produce intended and unintended environmental conservation and social equity outcomes. To do so, the team will use a mixed-methods approach that integrates a randomized controlled trial (RCT) with qualitative enquiries to assess conditional versus unconditional PES in 130 rural Bolivian communities.
External Link(s)

Registration Citation

Bauchet, Jonathan et al. 2021. "Co-producing environmental conservation and social equity: Is conditionality in Payments for Ecosystem Services a necessity or impediment?." AEA RCT Registry. December 20.
Experimental Details


The broad goal of this project is to determine how imposing conditions on program participants in Payments for Ecosystem Services (PES) programs affect program outcomes. This project will help us understand how conditionality in PES programs shapes human-environment relationships at the individual, household, and community scales. We also investigate the extent to which conditions in PES programs can be removed to still produce environmental benefits without increasing social inequalities.

We partner with Fundación Natura Bolivia (FNB), an environmental NGO operating PES programs in Bolivia and other Latin American nations, to examine conditional and unconditional versions of the same PES program that FNB is implementing. PES programs are typically conditional, that is they include monitoring compliance with the commitments taken by program participants in exchange for their receiving an incentive (cash or in-kind) from the program, and sanctions for non-compliance.

Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Rates of participation in the program
Adoption of conservation behaviors
Environmental conservation
Characteristics of participants (socio-economic)
Gender inequality in participation
Primary Outcomes (explanation)
% of households with a member signing up for the program

% of participating households with self-reported adoption of conservation behaviors promoted by the program, % of participating households with FNB-recorded adoption of conservation behaviors

Forest cover (acre)

Average total income of participating households, Average level of risk aversion of participants

% of households with a female member signing up, % of female participants reporting increased participation in household resource decision making (as one indicator of bargaining power within their household)

Secondary Outcomes

Secondary Outcomes (end points)
Perceived fairness in community
Secondary Outcomes (explanation)
% of households with a member reporting economic inequalities as a problem for their community, % of households with a member reporting feeling of exclusion

Experimental Design

Experimental Design
Out of a sample of 130 villages in 5 municipalities of the department of Santa Cruz in Bolivia, 65 communities were randomly offered the "normal" (i.e. conditional -- control group) program that FNB offered, and 65 other communities were offered an unconditional version of the program. The unconditional does not include monitoring visits to participants nor sanctions for non-compliance (one visit will be conducted at the end of the project to document compliance, but no sanction will be applied for non-compliance). All other aspects were kept identical (incentive amount and types, offer protocol, contract details, implementing staff, etc.). All land-owning households in a village are eligible to participate in the program; we did not alter participation conditions.

All 130 villages have participated in a previous RCT with FNB. The goal of that RCT was to measure the impacts of the program. It involved randomly offering the program in 65 communities, and keeping 65 communities as a control group where the program was not offered until the end of the RCT. All 130 communities were included in our project, and offered the program. In our RCT, we stratified the randomization by status in the previous RCT so that 1/2 of the communities offered the conditional program had previously been offered the same program and 1/2 of the communities offered the conditional program had never been offered FNB's program before; 1/2 of the communities offered the unconditional program had previously been offered a conditional version of the program and 1/2 of the communities offered the unconditional program had never been offered FNB's program before.
Experimental Design Details
Not available
Randomization Method
In office by a computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
130 villages
Sample size: planned number of observations
900 households
Sample size (or number of clusters) by treatment arms
65 villages control, 65 villages treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Power calculations suggest that 900 households in 130 village will allow us to capture medium effect sizes—differences in outcome variables of interest between treatment and control communities at the level of 0.4-0.5 standard deviation with 80% power (Cohen 1988). We based our power calculations on means, standard deviations, and intra-cluster correlations of key outcomes from previously collected data by FNB in the project area, a survey sample of 30% of households (for outcomes measured with survey data), and an assumption of 15% household attrition in the one to two years between contract sign-up and our survey.

Institutional Review Boards (IRBs)

IRB Name
Purdue University Human Research Protection Program
IRB Approval Date
IRB Approval Number