We investigate the phenomenon in which professional sports teams receive subsidies from cities to induce them to remain in the city. These subsidies often take the form of public funding for a new stadium. Using a dynamic model of bargaining with asymmetric threat points, we show that teams can extract increasing concessions from the city, culminating with the partial public funding of a new stadium. The model is consistent with many observed city/team bargaining relationships where lease renegotiations often favor the team over the city as teams use the threat of relocation as leverage in negotiations.