In this important new book, Ray Pawson examines the recent spread of evidence-based policy making across the Western world. Few major public initiatives are mounted these days in the absence of a sustained attempt to evaluate them. Programs are tried, tried, and tried again and researched, researched, and researched again. And yet it is often difficult to know which interventions, and which inquiries, will withstand the test of time. The evident solution, going by the name of evidence-based policy, is to take the longer view. Rather than relying on one-off studies, it is wiser to look to the 'weight of evidence'. Accordingly, it is now widely agreed the most useful data to support policy decisions will be culled from systematic reviews of all the existing research in particular policy domains. … Pawson presents a devastating critique of the dominant approach to systematic review - namely the 'meta-analytic' approach as sponsored by the Cochrane and Campbell collaborations. In its place is commended an approach that he terms 'realist synthesis'. On this vision, the real purpose of systematic review is better to understand program theory, so that policies can be properly targeted and developed to counter an ever-changing landscape of social problems. https://us.sagepub.com/en-us/nam/evidence-based-policy/book227875