Take a look at this chart, from Bard College economist Pavlina Tcherneva. In an August 2013 paper, she wrote
An examination of average income growth [in the U.S.] during every postwar expansion (from trough to peak) and its distribution between the wealthiest 10% and bottom 90% of households reveals that income growth becomes more inequitably distributed with every subsequent expansion during the entire postwar period.
In other words, the wealthy are capturing more and more of the overall income growth during each expansion period. Notice the sharp drop in the bottom 90 percent's share of growth starting with the 1982-1990 period — thanks, Reaganomics! Not only that, but the bottom 90 percent actually saw their real income drop between 2009 and 2012.
This chart doesn't necessarily tell us anything new — we've known for some time that income inequality has risen steadily during the postwar period. But this chart is a novel way of illustrating that fact.
Tcherneva will be presenting these numbers and others at the 12th Post Keynesian Conference this Saturday, which will be live-streamed.