In recent years, political parties and national legislatures in more than 100 countries have adopted quotas for the selection of female candidates to political office. Despite the rapid diffusion of these measures around the globe, most research has focused on single countries--or, at most, the presence of quotas within one world region. Due to limited evidence, explanations for adoption and impact of gender quotas derived from one study frequently contradict findings from other cases. Quotas for Women in Politics is the first book to address quotas as a global phenomenon in order to provide greater analytical leverage in explaining their spread and impact in diverse contexts around the world. It is organized around two sets of questions: First, why are quotas adopted? Which actors are involved in quota campaigns, and why do they support or oppose quota measures? Second, what effects do quotas have on existing patterns of political representation? Are these provisions sufficient for bringing more women into politics? Or, does their impact depend on other features of the broader political context? Synthesizing the literature on quota policies, Mona Lena Krook develops a framework for analyzing the spread of quota provisions and the reasons for variations in their effects. She then uses this framework to examine and compare different types of quota policies in Pakistan and India; Sweden and the United Kingdom; and Argentina and France.