Nobel Laureate Vernon Smith of Chapman University and George Mason University talks with EconTalk host Russ Roberts about the ideas in his new book, Rationality in Economics: Constructivist and Ecological Forms. They discuss the social and human sides of exchange, the robust nature of equilibrium in experiments and the real world, the seeming contradiction between Adam Smith's two great works, the unpredictability of how innovation emerges and its rationality, what neuroscience might tell us about economic decision-making, and the challenges of small-group intimate exchange and our interactions with strangers in the extended order of the marketplace.