Declining unionization caused one-third of increase in wage inequality during last 40 years

Nearly one-third of the increase in wage inequality among men over the last four decades is attributable to the declining unionization of the American workforce, a new study from the Economic Policy Institute found. Declining unionization is responsible for roughly one-fifth of the growth in wage inequality among women over the same time period (from 1973 to 2007), according to the report. In 1973, 26.7 percent of American workers were in a union; by 2011, that number had fallen to 13.1 percent. The study also found that declining unionization was responsible for 76 percent of the increase in wage inequality between white- and blue-collar workers.

http://thinkprogress.org/economy/2012/08/29/767631/report-declining-unionization-wages/

Nice to see this intuitive understanding backed up by the EPI study.