RT Journal Article SR Electronic T1 Monopsony in Movers: The Elasticity of Labor Supply to Firm Wage Policies JF Journal of Human Resources JO J Hum Resour FD University of Wisconsin Press SP 0319-10111R1 DO 10.3368/jhr.monopsony.0319-10111R1 A1 Ihsaan Bassier A1 Arindrajit Dube A1 Suresh Naidu YR 2021 UL http://jhr.uwpress.org/content/early/2021/04/05/jhr.monopsony.0319-10111R1.abstract AB We estimate the impact of the firm component of hourly wage variation on separations from matched Oregon employer-employee data. We use both firm fixed effects estimated from a wage equation as well as a matched IV event study around employment transitions between firms. Separations decline with firm wage policies: the implied firm-level labor supply elasticities are around 4, consistent with recent quasi-experimental evidence, but 3 to 4 times larger than existing estimates using individual wages. We find that monopsonistic competition is pervasive, even in low-wage, high turnover sectors, but with little heterogeneity by labor market concentration.