By Maggie Clark

Total union membership continued to decline this past year to 11.3 percent of all full-time wage and salary earners, down from 11.8 percent of all earners in 2011, according to the Bureau of Labor Statistics. The difference between membership levels for public and private employees was stark: 35.9 percent of public-sector employees were in unions, while only 6.6 percent of private-sector employees were union members, a report released Wednesday (January 23) said.

The numbers follow a trend of declining membership over the last 20 years. In 1983, just over 20 percent of workers were members of public-or-private-sector unions. The membership decline also mirrors the recent political defeats unions have suffered in Michigan, Indiana and Wisconsin.

The numbers were especially telling in Indiana, where the state passed a right-to-work law last year that allows workers to decide whether they want to join or financially support a union. Total union membership there declined by two percent in 2012, from 11.3 percent to 9.1 percent of all workers. The decrease in membership could be the first sign that the law is having the effects feared by Indiana unions, although anecdotally, some speculate the fights against the right-to-work legislation seem to have brought union members closer together.

Similarly, Wisconsin saw a two percent decline in union membership in 2012, following major restrictions on collective bargaining rights championed by Governor Scott Walker in 2011. The legislation was recently upheld by a federal court after challenges from the Wisconsin Education Association Council. The union argued that the law was discriminatory and unconstitutional. Another lawsuit against the collective bargaining changes is ongoing.

But in Oklahoma, which passed right-to-work legislation in 2001, union membership increased for the second consecutive year, up to 7.5 percent of employees belonging to a public or private sector union in 2012. Membership dipped during the recession, but is back up to its highest levels since 2002, according to the Bureau of Labor Statistics.

Unions continue to be strong in New York, which has the nation’s highest membership rate at 23.2 percent of all workers. Alaska and Hawaii also have more than 20 percent of workers in unions.

The states with the lowest membership are clustered in the South. North Carolina ranked last, with just 2.9 percent belonging to a union.