Thirty Years of Prospect Theory in Economics: A Review and Assessment

In 1979, Daniel Kahneman and Amos Tversky, published a paper in <em>Econometrica</em> titled "Prospect Theory: An Analysis of Decision under Risk." The paper presented a new model of risk attitudes called "prospect theory," which elegantly captured the experimental evidence on risk taking, including the documented violations of expected utility. More than 30 years later, prospect theory is still widely viewed as the best available description of how people evaluate risk in experimental settings. However, there are still relatively few well-known and broadly accepted applications of prospect theory in economics. One might be tempted to conclude that, even if prospect theory is an excellent description of behavior in experimental settings, it is less relevant outside the laboratory. In my view, this lesson would be incorrect. Over the past decade, researchers in the field of behavioral economics have put a lot of thought into how prospect theory should be applied in economic settings. This effort is bearing fruit. A significant body of theoretical work now incorporates the ideas in prospect theory into more traditional models of economic behavior, and a growing body of empirical work tests the predictions of these new theories. I am optimistic that some insights of prospect theory will eventually find a permanent and significant place in mainstream economic analysis.