Scientific discoveries over the past two decades have transformed the way in which researchers, policymakers, and the public think about early childhood. For example, recent research in brain science has provided a biological basis for prevailing theories about early child development, and cost-benefit analysis has reoriented some of the discussion about early childhood toward prevention programs. Several recent reports have been particularly helpful in translating research findings into practical information that improves policy. This paper summarizes the contributions from the field of economics, which has played an increasingly prominent role in recent discussions about early childhood policy. The insights from economics also have broader implications for social programs focused on prevention, especially during childhood, rather than later-in-life remediation. This research will be of value to individuals who are interested in early childhood policy, including decisionmakers in the public and private sectors, service providers, and the public more generally.