Jim Manzi, author of Uncontrolled, talks with EconTalk host Russ Roberts about the reliability of science and the ideas in his book. Manzi argues that unlike science, which can produce useful results using controlled experiments, social science typically involves complex systems where system-wide experiments are rare and statistical tools are limited in their ability to isolate causal relations. Because of the complexity of social environments, even narrow experiments are unlikely to have the wide application that can be found in the laws uncovered by experiments in the physical sciences. Manzi advocates a trial-and-error approach using randomized field trials to verify the usefulness of many policy proposals. And he argues for humility and lowered expectations when it comes to understanding causal effects in social settings related to public policy.