What Works in Social Policy?

Programs with credible evidence from well-conducted randomized controlled trials (RCTs) of important improvements in people’s lives

The Problem

Surprisingly few social programs, when rigorously evaluated, are found to produce the hoped-for improvements in participants’ lives. However, exceptional programs that produce important positive effects do exist.
To Help Address This Problem

This site seeks to identify those programs found in rigorous studies to produce sizable, sustained benefits to participants and society. The purpose is to enable policy officials and other readers to readily distinguish these programs from the many others that claim to have such evidence.
Our Process

We have identified these programs through our systematic monitoring of all rigorous evaluations published or posted online across all areas of social policy, and review of the most promising findings in consultation with outside experts. As a nonpartisan philanthropic organization, we receive no financial benefit from any program, enabling us to serve as an impartial reviewer.

Programs Organized by Policy Area

Top Tier

Programs shown in large, well-conducted RCTs to produce sizable, sustained effects on important outcomes. Top Tier evidence includes a requirement for replication – specifically, the demonstration of such effects in two or more RCTs in different implementation sites, or in one large multi-site RCT. Such evidence provides confidence that the program would produce important effects if implemented faithfully in settings and populations similar to those in the original studies.
Near Top Tier

Programs shown to meet almost all requirements for Top Tier, needing only one additional step to qualify. This category primarily includes programs meeting all elements of Top Tier in a single study site, but needing a replication RCT to confirm the initial findings and establish that they generalize to other sites. This is best viewed as tentative evidence that the program would produce important effects if implemented faithfully in settings and populations similar to those in the original...
Suggestive Tier

Programs that have been evaluated in one or more well-conducted RCTs and found to produce sizable positive effects, but whose evidence is limited by only short-term follow-up, effects that fall short of statistical significance, or other factors. Such evidence suggests the program may be an especially strong candidate for further research, but does not yet provide confidence that the program would produce important effects if implemented in new settings.