Employees, Firm Size, and Profitability in U.S. Manufacturing Industries

This study examines the relation between firm size and profitability within 109 SIC four-digit manufacturing industries.  Depending on our measure of profitability, we find that profitability increases at a decreasing rate and eventually declines in up to 47 of our industries.   No relation between profitability and size is found in up to 52 of our industries.  These two categories account for 97 of our 109 industries.  Profitability continues to increase as firms become larger in up to 11 industries.   Hence, the relation between size and profitability is industry specific.  But, regardless of the shape of the size profitability function, we find that profitability is negatively correlated with the number of employees for firms of a given size measured in terms of total assets and sales.