Debunking Skill-biased Technical Change
David Card, who always does excellent work, and John DiNardo published a nice work on the subject. Here is their conclusion:
133-40: “Since the late 1980s, a consensus has emerged that the decline in real wages for low-skilled workers in the early 1980s and the subsequent slow recovery of these wage levels are explained by skill-biased technological change. In this chapter, we have argued that the evidence underlying this consensus is remarkably frail. Much of the evidence takes the form of “proof by residual.” After accounting for changes in relative supply and (in some cases) making a modest list of other factors, proponents of this consensus note that the decline in the relative wages of low-skilled labor remains unexplained. Skill-biased technological change is then left as the only plausible explanation for the facts. Given the state of knowledge about how labor markets work, we find this line of argument unconvincing. Moreover, the evidence that emerges from such an exercise is highly model-specific. Depending on how the data for different groups are organized, the degree of substitution that is allowed between workers of different genders or ages, and the list of other job characteristics that are included in the decomposition, the results can suggest that rising inequality was either an ubiquitous phenomenon affecting virtually all workers over the past three decades or a trend that mainly affected young workers in the early 1980s.”
Card, David and John DiNardo. 2006. “The Impact of Technological Change on Low-Wage Workers: A Review.” In Rebecca M. Blank, Sheldon H. Danziger, and Robert F. Schoeni, editors. Working and Poor: How Economic and Policy Changes Are Affecting Low-Wage Workers (New York: Russell Sage Foundation): pp. 113-140.