This paper provides new estimates of depreciation rates for personal computers using an extensive database of prices of used PCs. Our results show that PCs lose roughly half their remaining value, on average, with each additional year of use. We decompose that decline into age-related...

The Producer Price Index (PPI) for the United States suggests that semiconductor prices have barely been falling in recent years, a dramatic contrast from the rapid declines reported from the mid-1980s to the early 2000s. This slowdown in the rate of decline is puzzling in light of evidence that...

Published macroeconomic data traditionally exclude most intangible investment from measured GDP. This situation is beginning to change, but our estimates suggest that as much as $800 billion is still excluded from U.S. published data (as of 2003), and that this leads to the exclusion of more...

The recent literature on the sources of economic growth has challenged the traditional growth accounting of the Solow model, which assigned a relatively limited role to capital deepening. As part of this literature, De Long and Summers have argued in two papers that the link between equipment...