David Autor of MIT talks with EconTalk host Russ Roberts about the Social Security Disability Insurance (SSDI) program. SSDI has grown dramatically in recent years and now costs about $200 billion a year. Autor explains how the program works, why the growth has been so dramatic, and the consequences for the stability of the program in the future. This is an illuminated look at the interaction between politics and economics and reveals an activity of government that is relatively ignored today but will not be able to be ignored in the future.