A Comment on 'The Intensity and Externality Effects of Information Technology Investments on National Productivity Growth'

摘要

The gross domestic product (GDP) deflator, which was used in the recent paper by J. Park, S. K. Shin, and H.-H. Shin, "The intensity and externality effects of information technology investments on national productivity growth," IEEE Trans. Eng. Manage., vol. 54, no. 4, November 2007, pp. 716-728, may not be appropriate for estimating real information technology (IT) investment because it does not reflect accurately the steep downward sloping price trend of IT. Moreover, the difference between the real IT investment by the GDP deflator and those by IT price index is increased as the time distance from a base year is increased. Using the real IT investment by the GDP deflator, there is a possibility of overestimating the effect of national IT capital on economic performance. The study should therefore have analyzed it using the real IT investment considering the steep downward sloping price trend of IT, or clearly included the assumption and limitations related to use of the GDP deflator in the paper.