In its 2011 annual report, the Congressional Budget Office found that from 1979 to 2007, average inflation-adjusted after-tax income had grown by 275 percent for the 1 percent of the population with the highest income. For others in the top 20 percent of the population, average real after-tax household income had grown by 65 percent.
By contrast, the CBO found that for the poorest fifth of the population, average real after-tax household income rose 18 percent.
And for the three-fifths of people in the middle of the income scale, the growth in such household income was just under 40 percent.
