Of the 20 most costly catastrophes since 1970, more than half have occurred since 2001. Is this an omen for the 21st century? How should we behave in this uncertain and dangerous environment? We’ll talk with Erwann Michel-Kerjan, Managing Director of the University of Pennsylvania’s Wharton Risk Center and author of the new book “The Irrational Economist: Making Decisions in a Dangerous World” (Public Affairs, 2010).