The percentage of U.S. workers who are members of a union fell from 11.8 percent to 11.3 percent in 2012, the Bureau of Labor Statistics announced Wednesday, in a continuation of a decades-long decline in union membership.
Despite an uptick in employment in 2012, the number of union workers also declined by 400,000, to 14.4 million.
Shortly after World War II, unions represented about one third of the workforce, according to Yale University political science professor Jacob Hacker. In 1983, according to the BLS, the union membership rate was 20.1 percent, with 17.7 million union workers. The union membership rate as calculated by the BLS has shown a consistant downward trend in recent years, from 13.4 percent in 2000 to 12.0 percent in 2006 to the current level of 11.3 percent.
The data also show a shift from unions representing private sector workers to pubic sector workers. In 2012, more private sector workers were unionized - 7.3 million - than public sector workers - 7.0 million - despite the fact that the vast majority of Americans are employed in the private sector.
"Working women and men urgently need a voice on the job today, but the sad truth is that it has become more difficult for them to have one, as today's figures on union membership demonstrate," AFL-CIO President Richard Trumka said in a statement.
Hacker, co-author of the book "Winner-Take-All Politics," said, "The long term trend is clear a result of more aggressive efforts by corporations to push back against unions or set up firms that are non-union in the first place."
Unions have been fighting mostly losing efforts in the past few years against attempts to curb their power, with laws passed in Wisconsin to limit collective bargaining rights of public sector employees and laws passed in Indiana and Michigan instituting "right to work" policies that prevent agreements in which employees are required to pay union dues.
Hacker said the fact that jobs have moved to "right to work" states and into industries that are not unionized has contributed to union decline.
"The real promise of unions is to be able to provide bargaining leverage to the great bulk of workers who are in the private sector," he said. "It's not clear with unions weakened who is going to provide that voice."
He added that private sector unions are now focused simply on survival.
"Unions are worried about whether they'll be here in the future," Hacker said, "instead of constructing a positive vision for the future."