An appeal for more rigorous use of counterfactual thinking in biological conservation

Abstract

It is vital to understand the consequences of actions intended to ensure biological conservation. Counterfactual thinking is increasingly used to establish the difference between the results of conservation action and the outcome if no action had been taken. In essence, a counterfactual is the outcome had a conservation action or treatment not been applied. The impact of a treatment is the difference that it makes to intended (or unintended) outcomes, relative to a counterfactual condition (Ferraro & Hanauer, 2015; Pressey, Visconti, & Ferraro, 2015). Since the use of counterfactual thinking is increasing steadily in conservation impact evaluation, we outline here five potential challenges to the rigorous application of the approach, which mainly stem from a failure to recognize that there may be multiple counterfactual states and that their construction requires care and transparency to ensure reproducibility.