Let's talk about facts: assessing the use of evidence in public policy

Abstract

Scholars and practitioners of public policy often assert that evidence – the full body of information with which policy actors engage to form and communicate their policy preferences – should be used in the process of public policy making. Furthermore, proponents of evidence-based policy state that evidence should be derived from methodologically rigorous sources. Despite this common decree, debate persists concerning which types of evidence should and are actually used by policy actors as well as the factors that influence its use. Normative differences among scholars have resulted in a disjointed approach to understanding the use of evidence in public policy as well as a lack of uniform discourse across disciplines. In response, I develop and integrative framework for assessing the use of evidence in public policy and test the framework by evaluating the use of evidence in the Diablo Canyon Nuclear Power Plant debate unfolding in San Louis Obispo County, California. The development of an integrative framework serves to unify the disparate scholars assessing the use of evidence by providing a common set of concepts that can be used to evaluate evidence use, interactions, and impacts. Subsequent analysis helps to not only test the efficacy of the framework but provides insight into who uses evidence where and when as well as what helps to predict evidence selection. The dissertation thus contributes to the existing literature on the use of evidence in public policy in two ways: by providing an integrative framework and advancing understanding of how evidence is used in public policy.