Prospect theory is an alternative theory of choice under conditions of risk, and deviates from expected utility theory by positing that people evaluate choices with respect to gains and losses from a reference point. They tend to overweight losses with respect to comparable gains and engage in risk-averse behavior with respect to gains and risk-acceptant behavior with respect to losses. They also respond to probabilities in a non-linear manner. I begin with an overview of prospect theory and some of the (...) evidence upon which it is based, and then consider some of the implications of the theory for American politics, international relations, and the law. I end with a brief discussion of some of the conceptual and methodological problems confronting the application of prospect theory to the study of politics. (shrink)