Self-selection: Are we beating a dead horse?

Abstract

Self-selection bias is a logical threat to the internal validity of an evaluation. Given the voluntary nature of participating in conservation programs, it is an issue that cannot generally be avoided. However, its importance is not as clear. This paper reviews some of the theoretical debate surrounding self-selection bias and methods to mitigate and control the problem. Given the other problems faced by professional evaluators, the paper concludes that the issue of self-selection should not undermine our confidence in the results of a well-designed evaluation.