The 400 richest Americans – the top 0.00025 percent of the population – have tripled their share of the nation's wealth since the early 1980s, according to a new working paper on wealth inequality by University of California at Berkeley economist Gabriel Zucman.
Those 400 Americans own more of the country's riches than the 150 million adults in the bottom 60 percent of the wealth distribution, who saw their share of the nation's wealth fall from 5.7 percent in 1987 to 2.1 percent in 2014, according to the World Inequality Database maintained by Zucman and others.
Overall, Zucman finds that "U.S. wealth concentration seems to have returned to levels last seen during the Roaring Twenties." That shift is eroding security from families in the lower and middle classes, who rely on their small stores of wealth to finance their retirement and to smooth over economic shocks like the loss of a job. And it's consolidating power in the hands of the nation's billionaires, who are increasingly using their riches to purchase political influence.