Labor union membership has sunk across the United States over the past 15 years for most jobs except legal workers, mathematicians, and, ironically, management, according to a study published Monday.
The Pew Research Center's new survey said that the number of union members in jobs classified as "management occupations" rose from 438,000 to 562,000 in the 2000-2014 period.
Over the same period, the number of union members in manufacturing jobs fell by nearly half to 1.1 million.
In another once relatively strongly unionized sector -- installation, maintenance and repair occupations -- the number of union members fell from 933,000 to 655,000, according to the study.
Overall union membership sank to 14.6 million people last year, or just 11 percent of the workforce, marking a steady slide since the peak of the labor movement in the 1950s, when nearly 35% were in labor unions.
Pew said the gain in management occupations involved not high-level executives but people deemed management because they had authority over others, including school administrators, construction foremen, food-service managers and other supervisory personnel.
And the rate of union membership in the category remains extremely low, at 4.5 %.
The losses in union jobs over the past three decades have all been in the private sector, while public sector unions remain strongest.
Many economists blame the growth in income disparity across the country to the weakening of unions. In the past three years unions have fueled a growing movement to force higher wages for low-paid workers in retail and fast-food service jobs.
Despite a decline in pro-union sentiment, the Pew study said more Americans still support the right to unionize.
Forty-eight percent have a favorable view toward unions, compared with 39% unfavorable. Just five years ago, more people had negative views of unions.
There was relatively stronger support for the right to unionize: 62% of people back fast-food workers in their right to set up and join unions, and 82% back the same rights for manufacturing and factory workers.
But only 45% of those surveyed say the fall in union membership has been bad, while 43% say it has been mostly good for the country.
Copyright 2015 Agence France-Presse