Labor Market Concentration

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.