NY Times covers new research by David Autor, Larry Katz et al:
"The researchers examined six industries that account for 80 percent of private employment in the United States. In each one, they discovered “a remarkably consistent upward trend in concentration.” In manufacturing, for instance, the top four companies controlled 43 percent of sales in 2012, up from 38 percent in 1982. In finance, the figure grew to 35 percent, from 24 percent, and in retail trade it went to 30 percent, from 15 percent. The faster concentration grew, the bigger the drop in labor’s share."