State government employees more likely to be union members than private sector
According to the Bureau of Labor Statistics, state government public-sector workers were 4.5 times more likely to be a member of a union that those in the private sector in 2011. In 2011, the overall union membership rate  was 11.8 percent and the membership rate for private-sector workers was 6.9 percent. The union membership rate for total public-sector workers (federal, state and local) was 37 percent in 2011, while the rate for state government public-sector workers was slightly lower at 32 percent.
Over the past decade, total public-sector union membership rates have remained fairly steady, hovering around 36-37 percent from 2001-2011. State government public-sector membership rates have also been relatively stable, growing one percentage point from 30.5 percent in 2001 to 31.5 percent in 2011. Private-sector membership rates, however, have dropped considerably over the past 10 years. In 2001, the private-sector union membership rate was 8.9 percent but fell to 6.9 percent by 2011, a 23 percent drop.
For reference, 84 percent of all workers over age 16 are private-sector, while the remaining 16 percent are public-sector (federal, state and local). Five percent of all workers are employed by state governments, or about one-third of all public-sector workers.
Author’s calculations of 2011 data from the Bureau of Labor Statistics
Workers in education, training, and library occupations had the highest unionization rate, at 36.8 percent, while those in sales and related occupations had the lowest rate at 3 percent. Black workers were more likely to be union members than were white, Asian, or Hispanic workers.
Overall union membership rates ranged from state to state in 2011. New York had the highest union membership rate at 24.1 percent followed by Alaska (22.1 percent) and Hawaii (21.5 percent). North Carolina had the lowest rate at 2.9 percent, with South Carolina (3.4 percent) and Georgia (3.9 percent) close behind.
Data Source: Bureau of Labor Statistics
 The percent of wage and salary workers age 16 and over who were members of a union.