Experiments and evaluation of public policies: Methods, implementation, and challenges

Evidence-based policymaking is all about developing and implementing better public policies. Although the logic underpinning this philosophy is simple, the practicalities of demonstrating causal effects of a public policy are much more complex. In recent years, there has been a wave of optimism about the usefulness of experimental approaches to public policy evaluation which mimics the clean, causal inferences observed in clinical trials. Although these methods, such as randomised controlled trials, have been widely advocated and implemented, they are not without their potential problems. In this paper, we consider the strengths, weaknesses, and challenges posed by the revolution in policy evaluation brought about by embracing experimental methods.