Larry Mishel has a systematic breakdown of the reasons for worker income stagnation since 1973. He starts with the familiar divergence: productivity up 80 percent, the compensation (including benefits) of the median worker up only 11 percent. Where did the productivity go?

The answer is, it’s two-thirds the inequality, stupid. One third of the difference is due to a technical issue involving price indexes. The rest, however, reflects a shift of income from labor to capital and, within that, a shift of labor income to the top and away from the middle.