The most important chart about the American economy you'll see this year

The most important chart about the American economy you'll see this year

Pavlina Tcherneva's chart showing the distribution of income gains during periods of economic expansion is burning up the economics internet over the past 24 hours and for good reason. The trend it depicts is shocking:

(Pavlina Tcherneva)

For a long time, most of the gains from economic growth went to the bottom 90 percent of the income distribution. And, after all, the bottom 90 percent includes the vast majority of people. Since 1980, that hasn't been the case. And for the first several years of the current expansion, the bottom 90 percent saw inflation-adjusted incomes continue to fall.
The data series ends in 2012 and we don't know how long the expansion will last, so that negative income trend may evaporate before all is said and done. But unless there's a massive break with the previous three expansions we will continue to have an economy where the typical family's living standards grow much more slowly than GDP growth per se would allow.