City Minimum Wages and Spatial Equilibrium Effects

Abstract

Local minimum wage laws are becoming common across U.S. cities, and their effects may be different from the effects of state or national minimum wage policies. This paper studies the effect of changes in the minimum wage on spatial equilibriums in local labor markets. Using residence and workplace data for the United States, I analyze how commuting, residence, and employment locations change across city and state borders if the minimum wage changes on one side of the border. I find that areas in which the minimum wage increases receive fewer low-wage commuters. A 10 percent increase in the minimum wage reduces the inflow of low-wage commuters by about 2.5 percent. Rises in the minimum wage are also associated with employment relocation across borders toward areas that did not witness an increase in the minimum wage. I formulate a spatial equilibrium gravity model to explain the distribution of workers between low- and high-minimum wage areas. I calculate counterfactual equilibriums with a higher minimum wage for U.S. counties with cities considering an increase, highlighting the role of commuting and migration responses. About two-fifths of the counties considering increases would receive fewer low-wage commuters. Employment relocation away from high-minimum wage areas drives the commuting losses.