Discussion of Matthew Rognlie: "Deciphering the Fall and Rise in the Net Capital Share": The Honest Broker for the Week of June 14, 2015, b J. Bradford DeLong: ... I was weaned on the education-deficit explanation of recent trends in US inequality, perhaps best set out by the very sharp Claudia Goldin and Larry Katz (2009) in The Race Between Education and Technology. In their view, the bulk of U.S. inequality trends since the 1980s were driven by education's losing this race. In the era that had begun in 1636 the United States-to-be had made increasing the educational level of the population a priority. But that era came to an end in the 1970s, while skill-biased technological change continues. That meant that the return to education-based skills began to rise. And it was that rise that was the principal driver of rising income inequality.
But, recently, reality does not seem to agree with what had once seemed to me to be a satisfactory explanation. First, to get large swings in the income distribution out of small changes in the relative supply of educated workers requires relatively low substitutability between college-taught skills and other factors of production. As inequality has risen, the required substitutability to fit the data has dropped to what now feels to me an unreasonably low magnitude. Second, while it is true that we have seen higher experience-skill premiums and sharply higher education-skill premiums, the real action in inequality appears now to be unduly concentrated in the upper tail. The distribution of the rise in inequality does not seem to match the distribution of technology-complementary skills at all. ...
Looking simply at my own family history, my Grandfather Bill reached not just the 1% or the 0.1% but the 0.01% back in the late 1960s in the days before the rise in inequality by selling his construction company to a conglomerate back in 1968. A good many of those of us who are his grandchildren have been very successful... But even should any of us be as lucky as my Grandfather Bill was in terms of our peak income and wealth as a multiple of median earnings, we would still be a multiple of his rank further down in the percentile income distribution.
Today, you need roughly 3.5 times the wealth now in the U.S. and 8 times the wealth worldwide to achieve the same percentile rank in the distribution... I find it simply impossible to conceptualize such an extreme concentration as in any way a return to a factor of production obtained as the product of "hours spent studying" times "brainpower", even when you also multiply by a factor "luck" and a factor "winner-take-all-economy".
So what, then, is going on and driving the sharp rise in inequality, if not some interaction between our education policy on the one hand and the continued progress of technology on the other? Thomas Piketty (2014) has a guess. Piketty guesses that the real explanation is that 1914-1980 is the anomaly. Without great political disturbances, wealth accumulates, concentrates, and dominates. The inequality trends we have seen over the past generation are simply a return to the normal pattern of income distribution in an industrialized market economy in which productivity growth is not unusually fast and political, depression, and military shocks not unusually large and prevalent. ...
[He goes on to talk about Matthew Rognlie's "Deciphering the Fall and Rise in the Net Capital Share."]