From field experiments to policy interventions at scale | Science

A major advance in recent decades in the social sciences has been the use of field experiments for causal evaluation of policy interventions. Such interventions might be targeted to individuals, households, or communities, and have become commonplace in development and labor economics. This has built an enormous body of knowledge of ‘what works’ as well as an understanding of mechanisms underlying ‘why it works’. If an intervention is evaluated to enhance welfare and be cost effective, then the next challenge is to understand whether the intervention will generate similar benefits at scale. Recent work has been laying the foundation for thinking about the science of scaling and understanding why interventions can fail to scale.