Jim Manzi writes in City Journal about using experiments in the social sciences to help make decisions like whether the economic stimulus in the United States was successful. Manzi writes:
Another way of putting the problem is that we have no reliable way to measure counterfactuals—that is, to know what would have happened had we not executed some policy—because so many other factors influence the outcome. This seemingly narrow problem is central to our continuing inability to transform social sciences into actual sciences. Unlike physics or biology, the social sciences have not demonstrated the capacity to produce a substantial body of useful, nonobvious, and reliable predictive rules about what they study—that is, human social behavior, including the impact of proposed government programs.
Manzi provides an overview of experimentation and discusses using randomized field trials. An interesting look at how we know – and don’t know – about the social world.