David Leonhardt, in an otherwise interesting post on slow economic growth and increasing inequality, “which has concentrated the economy’s modest gains among a small share of the population,” actually underestimates the increase in inequality over the course of the past three decades.
Here is what I’ve come up with (using average incomes for different income groups, in real 2010 dollars) in terms of percentage increases from 1980 to 2010 :
Top .01 percent: 502 percent
Top .1 percent: 301 percent
Top .5 percent: 190 percent
Top 1 percent: 154 percent
Bottom 90 percent: -4.5 percent
And, yes, while “since 2000, no income group has done particularly well,” the average income of the top .01 percent did increase 6.5 percent while the average income of the bottom 90 percent fell 13.5 percent.