In "Long-Run Changes in the U.S. Wage Structure: Narrowing, Widening, Polarizing" (
PDF), Lawrence Katz and Claudia Goldin argue that growing inequality in United States
is mostly due to skill-differentials but
isn't due to the dread skill-biased technological change. Rather, "the growth of the supply of skills slowed considerably after 1980 and the wage structure, in consequence, widened. The slowdown in the relative supply of skills of the working population came about largely from the slowdown in the growth in the educational attainment of U.S. natives for cohorts born since around 1950."
This article available online at:
http://www.theatlantic.com/politics/archive/2007/09/hot-new-inequality-research/46139/