Strong Employers and Weak Employees: How Does Employer Concentration Affect Wages?

We analyze the effect of local-level labor market concentration on wages.Using Census data over the period 1977-2009, we find that: (1) local-level employer concentration exhibits substantial cross-sectional and time-series variation and increases over time; (2) consistent with labor market monopsony power, there is a negative relation between local-level employer concentration and wages that is more pronounced at high levels of concentration and increases over time; (3) the negative relation between labor market concentration and wages is stronger when unionization rates are low; (4) the link between productivity growth and wage growth is stronger when labor markets are less concentrated; and (5) exposure to greater import competition from China (the "China Shock") is associated with more concentrated labor markets.These five results emphasize the role of local-level labor market monopsonies in influencing firm wage-setting behavior and can potentially explain some of the stagnation of wages in the United States over the past several decades.