This dissertation studies the determinants of the spatial distribution of economic activity and how such activity is affected by public policy. The dissertation contains three chapters. In the first chapter, we ask: what role does labor market competitiveness play in determining the location decisions of firms and workers, and the resulting spatial wage distribution? To answer this question, we develop a model of monopsony power in spatial equilibrium. Workers and firms are free to locate in any labor market, and the degree of market power a firm enjoys depends on the number of competing firms in its location. We show the model can rationalize concentrations of economic activity and the city-size wage premium through an endogenous labor ...