Marshall I. Steinbaum
1789 Lanier Pl, NW Apt 1
Washington, DC 20009
NBER Working Papers and Publications
|March 2018||Concentration in US Labor Markets: Evidence From Online Vacancy Data|
with José A. Azar, Ioana Marinescu, Bledi Taska: w24395
Using data on the near-universe of online US job vacancies collected by Burning Glass Technologies in 2016, we calculate labor market concentration using the Herfindahl-Hirschman index (HHI) for each commuting zone by 6-digit SOC occupation. The average market has an HHI of 3,953, or the equivalent of 2.5 recruiting employers. 54% of labor markets are highly concentrated (above 2,500 HHI) according to the DOJ/FTC guidelines. Highly concentrated markets account for 17% of employment. All plausible alternative market definitions show that more than 33% of markets are highly concentrated, suggesting that employers have market power in many US labor markets.
|December 2017||Labor Market Concentration|
with José Azar, Ioana Marinescu: w24147
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 over 8,000 geographic-occupational labor markets in the US. Based on the DOJ-FTC horizontal merger guidelines, the average market is highly concentrated. Using a panel IV regression, we show that going from the 25th percentile to the 75th percentile in concentration is associated with a 15-25% decline in posted wages, suggesting that concentration increases labor market power.