The Skill Content of Recent Technological Change : An Empirical Exploration

We apply an understanding of what computers do-the execution of procedural or rules-based logic-to study how computer technology alters job skill demands. We contend that computer capital (1) substitutes for workers in carrying out a limited and well-defined set of cognitive and manual activities, those that can be accomplished by following explicit rules (what we term "routine tasks"); and (2) complements workers in accomplishing non-routine problem solving and communications tasks. Provided these tasks are imperfect substitutes, our model implies measurable changes in the content of work, which we explore using representative data on job task input over the period 1960 to 1998. We show that computerization is associated with reduced relative demand for labor input of routine manual and routine cognitive tasks and increased relative demand for non-routine cognitive tasks. Demand shifts are evident within detailed industries, within detailed occupations, and within education groups within industries. Translating changes in job task content into education demand, the sum of within-industry and within-occupation shifts can account for forty percent of the estimated relative demand shift favoring college versus non-college labor during 1970 to 1998. Changes in task content within nominally identical occupations account for the largest component of this impact