The Economic Policy Institute says if union membership rates in the U.S. today were as high now as in 1979 non-union working people would get $133 billion more per year.

EPI has found that the decline of labor unions as a percent of the U.S. workforce has hurt both union and non-union wages. EPI's Larry Mishel.

[Larry Mishel]: "De-unionization has contributed about a third of the total growth of wage inequality among men. And if you look at women it's about 20 percent. So this is one of the largest factors that is measurable and identifiable in the growth of inequality. Increases trade with China and other low-wage countries lowered the wages by five percent for non-college educated workers."

The percentage of union workers in the workforce went from 34 percent in 1979 to 11 percent in 2013 for men. Sixteen percent to 6 percent among women.

EPI says the decline in unions has not only hurt workers in those unions, but it's hurt non-union worker wages too. EPI says all workers benefit from the right of unions to collectively bargain.