RT Journal Article SR Electronic T1 Strong Employers and Weak Employees JF Journal of Human Resources JO J Hum Resour FD University of Wisconsin Press SP S200 OP S250 DO 10.3368/jhr.monopsony.0119-10007R1 VO 57 IS S A1 Efraim Benmelech A1 Nittai K. Bergman A1 Hyunseob Kim YR 2022 UL http://jhr.uwpress.org/content/57/S/S200.abstract AB We analyze the effect of local-level labor market concentration on wages. Using plant-level U.S. Census data during 1978–2016, we find that: (i) local-level employer concentration exhibits substantial cross-sectional variation; (ii) consistent with labor market monopsony power, there is a negative relation between local-level employer concentration and wages that strengthens with time; (iii) instrumenting concentration with merger activity shows that increased employer concentration decreases wages; (iv) the negative relation between employer concentration and wages increases when unionization rates are low; and (v) the link between productivity growth and wage growth is stronger when labor markets are less concentrated. Our results emphasize the role of local labor market monopsonies in influencing firm wage-setting.