On Sturdy Policy Evaluation

This paper provides an overview of different approaches to policy evaluation. We focus on how different types of uncertainty should be accounted for in the policy evaluation process. Appropriate incorporation of uncertainty in policy evaluation leads to what we call sturdy decisions. We describe classical Bayesian decision theory and decision theory under ambiguity. We provide examples ranging from the deterrent effect of capital punishment to Food and Drug Administration approval rules to environmental policy to illustrate the conceptual framework we present. Throughout, the role of judgment in any formal approach to policy evaluation is emphasized.