Recent research makes it clear that the American Dream of upward mobility, which was real in earlier generations, is greatly diminished today. To take just one example, a 2013 study of U.S. tax returns from 1987 to 2009 conducted by economists Jason DeBacker, Bradley Heim, and their colleagues found that the thirty-five thousand households they studied tended to stay in roughly the same order of richest to poorest year after year, with little reshuffling, even as the differences in household income grew over time.
