INTRODUCTION

Experimental criminology is a part of a larger and increasingly expanding evidence-based movement in social policy. The evidence-based movement first began in medicine and has, more recently, been embraced by the social sciences. Evidence-based social policy advocates – in areas such as education, poverty reduction, and crime prevention – are dedicated to increasing the use of scientific evidence in the implementation of government programs so critical social problems can be addressed without wasting scarce taxpayer funds. Experimental criminologists, and organizations such as the Academy of Experimental Criminology and the Campbell Collaboration’s Crime and Justice Group, have been leading advocates for the advancement of evidence-based crime control policy in general and the use of randomized experiments in crime and justice research in particular.

Experimental criminology has, for the most part, moved past the first wave of criticism that questioned the use of randomized controlled trials (RCTs) in crime and justice evaluations. Two key concerns were that (1) it was not ethical to randomize treatments, interventions, or programs in crime and justice; and (2) randomized experiments could not be implemented in the real world (Clarke and Cornish 1972; Esbensen 1991; Erez 1986; Geis 1967). As Weisburd (2010) recently argued, the growth of criminological experiments in a broad range of real-world settings that have been carried out in an ethical manner demonstrates that these concerns are, in most cases, based in folklore rather than facts. However, as the influence of randomized experiments in crime and justice has grown in recent years, a second wave of criticism has been increasingly articulated by criminologists concerned by the field’s experimental turn. These critiques share a common concern that experimental criminology blindly advocates the superiority of RCTs over quasi-experiments and observational studies.