What role should Randomised Control Trials play in providing the evidence base underpinning conservation?
- Published
- Accepted
- Subject Areas
- Conservation Biology, Ecology, Coupled Natural and Human Systems, Natural Resource Management
- Keywords
- Impact Evaluation, Evidence-Based Conservation, Counterfactual, RCT, Environmental Management, Evidence-Informed Policy, Randomised Control Trial, Randomised Controlled Trial
- Copyright
- © 2018 Pynegar et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. What role should Randomised Control Trials play in providing the evidence base underpinning conservation? PeerJ Preprints 6:e26929v1 https://doi.org/10.7287/peerj.preprints.26929v1
Abstract
There is general agreement that conservation decision-making should be evidence-informed, but many evaluations of intervention effectiveness do not attempt to account for confounding variables and so provide weak evidence. Randomised Control Trials (RCTs), in which experimental units are randomly allocated to treatment or control groups, offer an intuitive means of calculating the effect size of an intervention through establishing a reliable counterfactual and avoid the pitfalls of alternative quasi-experimental approaches. However, RCTs may not be the most appropriate way to answer some kinds of evaluation question, are not feasible in all circumstances, and factors such as spillover and behavioural effects risk prejudicing their quality. Some of these challenges may be greater in situations where the intervention aims to influence ecological outcomes through changing human behaviour (socio-ecological interventions). The external validity – the extent to which findings are generalizable – of RCT impact evaluation has also been questioned. We offer guidance and a series of criteria for deciding when RCTs may be a useful approach for evaluating the impact of conservation interventions, and what must be considered to ensure an RCT is of high quality. We illustrate this with examples from one of the few RCTs of a socio-ecological intervention – an incentive-based conservation program in the Bolivian Andes. Those who care about evidence-informed environmental management should aim to avoid a re-run of the polarized debate surrounding RCTs’ use in fields such as development economics and take a pragmatic approach to impact evaluation, while also actively integrating learning from these fields. If this can be achieved, they will have a useful role to play in robust impact evaluation.
Author Comment
In this opinion piece, we discuss the use of Randomised Control Trials (RCTs, also known as Randomised Controlled Trials) in conservation and environmental management. We review the literature from fields in which RCTs are more widely used, such as medicine, development economics, labour economics, and psychology, and contextualise relevant issues from this for the conservation field. This piece is aimed principally at conservation practitioners interested in evaluating programs using randomised methods, and as such introduces RCTs from scratch and directs interested parties to other, more detailed, literature explaining their implementation. To facilitate this we provide a checklist or flow diagram of seven principal issues relating to RCTs’ advisability, feasibility and quality that we believe are critical for implementers to consider when deciding upon impact evaluation methods. We also, however, intend our piece to serve as a guide for researchers and funding bodies in considering RCT quality. We illustrate these theoretical issues with the example of one of the very few large-scale examples of a socio-ecological RCT of a conservation intervention, the case of Watershared in the Bolivian Andes (Asquith, 2016, Grillos, 2017, and Bottazzi et al., 2018).
We would welcome any comments or contributions from the PeerJ community in helping us improve this piece.
Asquith, N.M. 2016. Watershared: Adaptation, mitigation, watershed protection and economic development in Latin America. London: Climate & Development Knowledge Network.
Grillos T. 2017. Economic vs non-material incentives for participation in an in-kind payments for ecosystem services program in Bolivia. Ecological Economics 131:178–190.
Bottazzi P., Wiik E., Crespo D., Jones JPG. 2018. Payment for Environmental “Self-Service”: Exploring the Links Between Farmers’ Motivation and Additionality in a Conservation Incentive Programme in the Bolivian Andes. Ecological Economics 150:11–23.
