This new NBER working paper by Claudia Goldin and Larry Katz just made it to the top of the must-read pile. The title and abstract (with my emphasis added):
Long-Run Changes in the U.S. Wage Structure: Narrowing, Widening, Polarizing
The U.S. wage structure evolved across the last century: narrowing from 1910 to 1950, fairly stable in the 1950s and 1960s, widening rapidly during the 1980s, and “polarizing” since the late 1980s. We document the spectacular rise of U.S. wage inequality after 1980 and place recent changes into a century-long historical perspective to understand the sources of change. The majority of the increase in wage inequality since 1980 can be accounted for by rising educational wage differentials, just as a substantial part of the decrease in wage inequality in the earlier era can be accounted for by decreasing educational wage differentials.
Although skill-biased technological change has generated rapid growth in the relative demand for more-educated workers for at least the past century, increases in the supply of skills, from rising educational attainment of the U.S. work force, more than kept pace for most of the twentieth century. Since 1980, however, a sharp decline in skill supply growth driven by a slowdown in the rise of educational attainment of successive U.S. born cohorts has been a major factor in the surge in educational wage differentials. Polarization set in during the late 1980s with employment shifts into high- and low-wage jobs at the expense of the middle leading to rapidly rising upper tail wage inequality but modestly falling lower tail wage inequality.
The sentences that I have highlighted seem directly relevant to this earlier discussion in August 2006 about whether Paul Krugman was right to accuse Treasury Secretary Paulson of "falsely implying that rising inequality is mainly a story about rising wages for the highly educated." (See follow up posts here and here.)
I'll look forward to reading the paper and revisiting the broader issue.