The recent rise in wage inequality is usually attributed to skill-biased technical change (SBTC), associated with new computer technologies. We review the evidence for this hypothesis, focusing on the implications of SBTC for overall wage inequality and for changes in wage differentials between groups. A key problem for the SBTC hypothesis is that wage inequality stabilized in the 1990s despite continuing advances in computer technology; SBTC also fails to explain the evolution of other dimensions of wage inequality, including the gender and racial wage gaps and the age gradient in the return to education.

A special exemption from the 1986 Age Discrimination Act allowed colleges and universities to enforce mandatory retirement of faculty at age 70 until 1994. We construct a survey that permits us to compare faculty turnover rates before and after the law changed at a large sample of institutions with defined contribution pension plans. After the elimination of compulsory retirement the retirement rates of 70- and 71-year-olds fell by two-thirds and were comparable to rates of 69-year-olds. These findings indicate that U.S. colleges and universities will experience a rise in the number of older faculty over the coming years.