In China, deepening market reforms have sanctioned the mass migration of 210 million peasants to cities, the largest single migration in world history. However, it is not those who move, but those left behind as others move around them, that make labor migration both possible and profitable. Since migrants lack substantive rights to cities, their mobility is underwritten by the affective support and agricultural earnings of left-behind spouses and kin. Seen from the standpoint of the immobile, departure is a site saturated with normativity surrounding migrants’ obligations to those left behind. Interactions between the mobile and the immobile produce a politics of departure, negotiating conditions of departure around logics of progress and obligation, and framing decisions to “leave to earn” or to “return with fidelity.” This politics of departure transforms migration into a moral project, making mobility for some a debt to be repaid, for others a project of self-improvement with failure in return. In impoverished Butuo County in southwest China, scandal surrounds the absent. A local myth told among left-behind kin concerns village men who are said to have sold their own kin into bonded labor for profit. Blame for a growing number of unmarriageable bachelors tied to the land of their fathers is assigned to exogamous brides marrying out. Meanwhile, in nearby, prosperous Qianwei County, gossip focuses on prematurely returned migrants who have returned home after “failed” migrations. Villagers valorize the absent, and scorn those returned who are seen as freeloading off their elderly farming kin at home. Through a comparative ethnography of the politics of departure in Qianwei and Butuo, this dissertation provides an analysis of the political economy of migration from the standpoint of those left behind, and reveals migration to be irrevocably shaped by the moral debts, expectations, and obligations which make departures possible.