The following article by Richard Freeman, Eunice Han, Brendan Duke and David Madland appeared on the Center for American Progress website on January 13, 2016:
The United States has long called itself a middle-class nation. But that statement is less true today than it was 30 years ago.
The most widely used barometer of the financial health of the middle class—real median household income as published by the U.S. Census Bureau—has barely grown over the last thirty years. At the same time, the middle class has been hollowed out as incomes have polarized, with more households at the top and the bottom and fewer in the middle of the income distribution. A recent report by the Pew Research Center showed that the share of adults in the middle class—defined as adults whose households make between 67 percent and 200 percent of median U.S. income—fell from 61 percent in 1971 to just 50 percent in 2014.
Unsurprisingly, the same trends of slow growth and rapid polarization are also found in the main source of middle-class income: wage and salary earnings. Median weekly earnings of full-time workers grew 18 percent between 1984 and 2014 despite a 79 percent increase in labor productivity