This article is based on a study by Bart van Ark, Robert Inklaar and Robert H. McGuckin (2002a), "Changing Gear: Productivity, ICT and Service: Europe and the United States," Research Memorandum GD60, Groningen Growth and Development Centre (downloadable from http://www.eco.rug.nl/ggdc).

From its inception, the Penn World Tables (PWT), building on the International Comparisons Program (ICP) of the United Nations, has sought to compare the standard of living of individuals in different countries. That is, the term"real GDP per capita"as reported in the PWT is intended to...