TY - JOUR T1 - Labor Market Concentration JF - Journal of Human Resources JO - J Hum Resour SP - S167 LP - S199 DO - 10.3368/jhr.monopsony.1218-9914R1 VL - 57 IS - S AU - José Azar AU - Ioana Marinescu AU - Marshall Steinbaum Y1 - 2022/04/01 UR - http://jhr.uwpress.org/content/57/S/S167.abstract N2 - A product market is concentrated when a few firms dominate the market. Similarly, a labor market is concentrated when a few firms dominate hiring in the market. Using data from the leading employment website CareerBuilder.com, we calculate labor market concentration for more than 8,000 geographic–occupational labor markets in the United States. Based on the Department of Justice–Federal Trade Commission horizontal merger guidelines, the average market is highly concentrated. Going from the 25th percentile to the 75th percentile in concentration is associated with a 5 percent (OLS) to 17 percent (IV) decline in posted wages, suggesting that concentration increases labor market power. ER -