Theories in political economy depend critically on assumptions about motivations of politicians. Our analysis starts from the premise that politicians, like other economic agents, are rational individuals who make career decisions by comparing the expected returns of alternative choices. The main goal of the paper is to quantify the returns to a career in the United States Congress. To achieve this goal we specify a dynamic model of career decisions of a member of Congress and we estimate this model using a newly collected data set. Given estimates of the structural model, we assess reelection probabilities for members of Congress, estimate the effect of congressional experience on private and public sector wages, and quantify the value of a congressional seat. Moreover, we use the estimated model to assess how an increase in the congressional wage or the imposition of term limits would affect the career decisions of politicians and the returns to a career in Congress.