The new randomised controlled trials (RCT) movement in public policy: challenges of epistemic governance

Since 2012, a new movement of government departments, think tanks and high-profile individuals within the UK has sought to promote the increased usage of randomised controlled trials (RCTs) in public policy. They promote RCTs as an evidence-based corrective for the inappropriate certainties of experts. Recent government reports and public debate around this initiative are reviewed and analysed within a framework for epistemic governance: normative insights into how knowledge for policymaking should be understood and governed drawn from science and technology studies and the policy sciences. The legitimacy of RCT evidence within policymaking is found to rest on the recognition of three key features: (1) how multiple meanings of evidence limit generalisability, (2) ensuring a plurality of evidence inputs, including those from other forms of research and expertise, and (3) building institutions for governing the use of RCTs in the public interest. Producing evidence for policymaking is a hybrid activity that necessarily spans both science and politics. Presenting RCTs as naively neutral evidence of what policy interventions work is misleading. The paper concludes by calling for more work on how the new RCT movement might engage with its own history in social and policy research on the value of experiments for policymaking.