Information Technology and the U.S. Productivity Revival: What Do the Industry Data Say?

摘要

IT has emerged as an appealing candidate to explain the acceleration of U.S. productivity growth in recent years and these results strengthen that view by establishing a link between IT capital and subsequent productivity growth across U.S. industries. In particular, industries that made the largest investments in computer hardware, software, and telecommunication equipment in the 1980's and early 1990's show larger productivity gains after 1995. A decomposition of aggregate productivity growth into the contribution of individual industries and interindustry reallocation effects shows that IT-producing and IT-using industries account for all of the productivity revival that is attributable to the direct contributions from specific industries. In sharp contrast, industries that are relatively isolated from the IT revolution made a negative contribution to the U.S. productivity revival on net. While IT is clearly not the only force behind the U.S. productivity revival, these results suggest that it is probably an important one. This evidence also supports the idea that the acceleration of aggregate productivity is a real phenomenon and not just a cyclical one. Given the substantial differences in productivity growth between IT-intensive and other industries, cyclical forces would have to be highly concentrated in precisely those industries that are most IT intensive for this to be the whole story. The strong and robust correlation between IT intensity and the subsequent productivity acceleration, however, implies that there may be a deeper relationship between IT investment and productivity growth.