Jim Manzi, founder and chair of Applied Predictive Technologies, senior fellow at the Manhattan Institute, and author of Uncontrolled, talks with EconTalk host Russ Roberts about the Oregon Medicaid study and the challenges of interpreting experimental results. Manzi notes a number of interesting aspects of the study results that have generally been unnoticed--the relatively high proportion of people in the Oregon study who turned down the chance to receive Medicaid benefits, and the increase (though insignificant) in smoking by those who received Medicaid benefits under the experiment. Along the way, Manzi discusses general issues of statistical significance, and how we might learn more about the effects of Medicaid in the future.