What are the political consequences of international migration on the migrant's country of origin? To help understand this question, this review article first examines data and measurement issues that have hampered empirical analysis. It then lays out an analytical framework outlining four channels through which migration's political consequences play out: the prospective, absence, diaspora, and return channels. The article next delineates the variables that attenuate or amplify these effects and argues that unobservable characteristics, in particular who leaves and why, have an important influence on the type and intensity of political effects. Subsequently, the article examines some key political consequences of international migration: its political economy consequences, its impact on conflict, and its institutional effects, focusing on political institutions as well as nationalism and citizenship. The penultimate section points out the importance of temporality in understanding the political effects o...