Daniel Kahneman is Eugene Higgins Professor of Psychology, Emeritus, Princeton University and winner of the 2002 Nobel Prize in Economics. Responding will be Jon Elster, Robert K. Merton Professor of Social Sciences,Columbia University; George Ainslie, Chief Psychiatrist, Veterans Affairs Medical Center Coatesville, PA and Clinical Professor of Psychiatry, Temple University; and Walter Mischel, Niven Professor of Humane Letters in Psychology, Columbia University.