Among private industries, the union membership rate was the highest in transportation and public utilities in 2002, at 23 percent. Of all wage and salary workers in private industry, 8.5 percent were union members in 2002.
The construction and manufacturing industries also had higher-than-average unionization rates, at 17.2 percent and 14.3 percent, respectively. The industry with the lowest unionization rate in 2002 was finance, insurance, and real estate—1.9 percent. Other private industries with below-average unionization rates were agriculture; wholesale and retail trade; and services.
In contrast to private industry, 37.5 percent of government workers were union members in 2002.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Union membership in private industry, 2002 at https://www.bls.gov/opub/ted/2003/feb/wk4/art03.htm (visited December 08, 2023).