Employment Cost Index (ECI) data show that union pay consistently rose more rapidly than nonunion pay between 1975 and 1982. In contrast, between December 1982 and March 1999, nonunion pay has generally risen faster.
Although union wages have not risen as rapidly as nonunion wages in recent years, they are still higher. Data for March 1999 from the Employer Costs for Employee Compensation program show that wages and salaries for union workers in the private sector averages $16.21 per hour compared to $13.54 for nonunion workers.
Moreover, data from the 1997 National Compensation Survey show that union workers enjoyed a salary advantage over nonunion in almost all occupations.
These data are a product of the National Compensation Survey. Differences in wages between union and nonunion workers may reflect factors other than union representation. Among the factors are the specific mix of occupational categories, the mix of full- and part-time workers, the size and specific industry of the employer, and the establishment’s geographic location. Find out more in Ann C. Foster, "Union-nonunion Wage Differences, 1997" (PDF 61K), Compensation and Working Conditions, Spring 2000.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Union-nonunion wage gap narrows at https://www.bls.gov/opub/ted/2000/apr/wk4/art02.htm (visited December 06, 2022).