This is the first book to present a synthesis of rational choice theory and sociological perspectives for the analysis of social institutions. The origin of social institutions is an old concern in social theory. Currently it has re-emerged as one of the most intensely debated issues in social science. Among economists and rational choice theorists, there is growing awareness that most, if not all, of the social outcomes that are of interest to explain are at least partly a function of institutional constraints. Yet the role of institutions is negligible both in general equilibrium theory and in most neoclassical economic models. There is a burgeoning substantive interest in institutions ranging from social movements, to formal organizations, to states, and even international regimes. Rational choice theorists have made great strides in elucidating the effects of institutions on a variety of social outcomes, but they have paid insufficient attention to the social dynamics that lead to the emergence of these institutions. Typically, these institutions have been assumed to be a given, rather than considered as outcomes requiring explanation in their own right. Sociological theorists, in contrast, have long appreciated the role of social structural constraints in the determination of outcomes but have neglected the role of individual agents.