The Role of Evidence in Theories of the Policy Process

Abstract

This chapter identifies an ‘ideal-type’ of evidence-based policymaking (EBPM) and the factors required to produce an ‘optimal’ policy process. It compares this image with more realistic accounts of policymaking based on theoretical and empirical policy studies. These studies provide two main ways to understand EBPM: one explains the ‘evidence-policy gap’ with reference to key problems with the demand and supply of evidence; the other identifies the cognitive limits of policymakers, and an unpredictable policymaking environment. From this discussion, the chapter identifies three key tenets of EBPM to guide further analysis.