Evaluating Environmental Policies

For too long, environmental policymaking has relied on trial and error, without adequate or systematic learning from either the trials or the errors. Systematic program evaluation research has been remarkably scarce relative to the overall number of environmental policies adopted in the United States, as well as relative to the amount of evaluation research found in other fields, such as medicine, education, or transportation safety. This paper examines the role that program evaluation should play in environmental policy making, distinguishing such research from other types of analysis, including risk assessment, cost-effectiveness analysis, and cost-benefit analysis. It explains the kinds of methodological practices that researchers should use to isolate the causal effects of particular environmental regulations and policies. By adhering to the program evaluation methods discussed in this paper, researchers will be better able to isolate the effects of specific policy interventions and help inform future policy decisions. A renewed and expanded commitment to program evaluation of environmental policy is needed to move environmental policy making closer to an evidence-based practice, and conditions are probably more ripe now for fostering such a commitment than they have ever been before.