Chatham House · CC BY 2.0

An economist who helped build behavioral economics into a serious discipline, working with psychologists Daniel Kahneman and Amos Tversky to show how real people's decisions systematically depart from the perfectly rational actor that classical economics assumes. His research on those predictable departures — and how small changes in how choices are presented can nudge people toward better outcomes — won him the 2017 Nobel Memorial Prize in Economic Sciences. He has taught at the University of Chicago and served as president of the American Economic Association.