We use a large project-level dataset to estimate the length of the planning period for commercial construction projects in the United States. We find that these time-to-plan lags are long, averaging about 17 months when we aggregate the projects without regard to size and more than 28 months...

Regressions of investment on Tobin's Q are misspecified in the presence of capital gestation lags because they don't distinguish between the value of existing capital and the value of capital at a future date. Current investment should be determined by the anticipated shadow value of capital at...

Investment models typically assume that capital becomes productive almost immediately after purchase and that there is no lead time needed to plan. In the case, marginal q is usually sufficient for investment. This paper develops a model of aggregate investment where competitive firms face no...

Business outlays on intangible assets are usually expensed in economic and financial accounts. Following Hulten (1979), this paper develops an intertemporal framework for measuring capital in which consumer utility maximization governs the expenditures that are current consumption versus those...

The composition of the U.S. population will change significantly in coming decades as the decline in fertility rates following the baby boom, coupled with increasing longevity, leads to an older population. This demographic shift will likely have a dramatic effect on the long-run prospects for...

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...

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...

This paper examines three questions motivated by previous research on semiconductors and productivity growth: Why did semiconductor prices fall so rapidly in the second half of the 1990s, why has the rate of price decline slowed since 2001, and to what extent are these price swings associated...

We use earnings forecasts from securities analysts to construct more accurate measures of the fundamentals that affect the expected returns to investment. We find that investment responds significantly -- in both economic and statistical terms -- to our new measures of fundamentals. Our...