On January 21, 2011, the U.S. Bureau of Labor Statistics (BLS) reported that in 2010 union membership as a percentage of all workers including public and private sectors declined from 2009.  Thus, in 2009, that percentage was 12.3, but in 2010 it dropped to 11.9.  The U.S. Bureau of Labor Statistics reported also that the number of workers belonging to unions declined by 612,000 to a total of 14.7 million. In 1983, the first year for which such data was available, the union membership rate was 20.1%, and there were 17.7 million union workers.

In 2010, for the first time, there were more public sector union members than in the private sector: 7.6 million versus 7.1 million. And in 2010, the union membership rate for public sector employees was 36.2% as compared to the rate for private sector workers at 6.9%.

In the private sector, union membership as a percentage of all private sector workers went from 7.2% in 2009 to 6.9% in 2010.

In 2010, 31 states and the District of Columbia had union membership rates below that of the U.S. average, 11.9%, while 19 states had higher rates. All states in the Middle Atlantic and Pacific areas reported union membership rates above the national average, and all states in the East South Central and West South Central areas had rates below it.

Eight states had union membership rates (combining both public and private sectors) below 5% in 2010, with North Carolina having the lowest rate at 3.2%. The next lowest rates were in Arkansas and Georgia each at 4%, Louisiana at 4.3%, Mississippi at 4.5 %, South Carolina and Virginia each at 4.6%, and Tennessee at 4.7%. The membership rate in Kentucky was 8.9% and in Indiana was 10.9%. Six states had union membership rates over 17.0 percent in 2010: New York at 24.2% (the highest rate), Alaska at 22.9%, Hawaii at 21.8%, Washington at 19.4%, California at 17.5%, and New Jersey at 17.1%.

The largest numbers of union members lived in California with 2.4 million, and New York with 2 million. About half of the 14.7 million union members in the U.S. live in just 6 states: California, New York, Illinois, Pennsylvania, Ohio, and New Jersey.

 BLS reported that the data on union membership were collected as part of the Current Population Survey, a monthly sample survey of about 60,000 households that obtains information on employment and unemployment among the nation’s civilian non-institutional population age 16 and over.