In 2005, workers in the public sector had a union membership rate much higher than that of private-sector employees.
The unionization rate for government workers was 36.5 percent in 2005, while the rate for private industry workers was 7.8 percent.
Within the public sector, local government workers had the highest union membership rate (41.9 percent). This group includes several heavily unionized occupations, such as teachers, police officers, and fire fighters.
Among major private industries, transportation and utilities had the highest union membership rate, at 24.0 percent. Information industries (13.6 percent), construction (13.1 percent), and manufacturing (13.0 percent) also had higher-than-average rates.
Bureau of Labor Statistics, U.S. Department of Labor, The Economics Daily, Union membership by industry, 2005 at https://www.bls.gov/opub/ted/2006/jan/wk4/art02.htm (visited December 06, 2022).