By now the whole wonky set is familiar with the stylized fact that for thirty years after World War II, productivity gains fed into higher earnings for the media worker. In the past thirty years, that hasn’t been the case. But people rarely dive deep into the question of where the “missing” gains went. A great report that Larry Mishel wrote for the Economic Policy Institute last week does the work and the answer is pretty interesting. Rather than a single cause, there are three separate sources of divergence. One is structural shift in which labor claims a smaller share of national economic output and capital claims a larger share. A second is a shift within the labor share toward greater inequality such that the mean wage rises faster than the median wage. And a third is a very interesting phenomenon that has to do with the existence of different inflation indexes.