Economic theories often inform policy choices, but events can call into question these same theories. In this episode of EconoFact Chats, John Cassidy, Staff Writer for The New Yorker joins Michael Klein to discuss how policies based on the advantages of unfettered free markets were challenged by the 2008 financial and economic crisis.  John also discusses other instances of challenges to theories; for example how evidence has given rise to behavioral economics, and the role of psychology and information to guide policy.  John is the author of How Markets Fail: The Logic of Economic Calamities and Dot.Con: How America Lost Its Mind and Money in the Internet Era.