FUNDAMENTALLY TRANSFORMED: Pew: The American Middle Class Is Losing Ground. “In at least one sense, the shift represents economic progress: While the share of U.S. adults living in both upper- and lower-income households rose alongside the declining share in the middle from 1971 to 2015, the share in the upper-income tier grew more. Over the same period, however, the nation’s aggregate household income has substantially shifted from middle-income to upper-income households, driven by the growing size of the upper-income tier and more rapid gains in income at the top.”