This strategy requires a pipeline of social programs that have been tested and shown to be effective by rigorous evaluations. However, experience shows that most social programs, including some of the most celebrated such as DARE and Head Start, produce modest or no impacts that last when subjected to rigorous evaluations. An important virtue of focusing on evidence is not simply that the public will have reliable information about whether programs work, but that the evidence places pressure on programs to change and improve when they are not working.
