Evolution of technology causes human capital to become obsolete. We study this phenomenon in an overlapping generations setting, assuming it is hard to predict how technology will evolve, and that older workers find updating uneconomic. Among our results is the proposition that (under certain...

The usual explanation for why the producers of a given product use different technologies involves "vintage-capital": A firm understands the frontier technology, but can still prefer an older, less efficient technology in which it has made specific physical and human capital investments. This...

Firm numbers first rise, and then fall as the typical industry evolves. This nonmonotonicity in the number of producers is explained in this paper using a competitive model in which innovation opportunities induce firms to enter, but in which a firm's failure to implement new technology causes...

We estimate the volatility of plant-level idiosyncratic shocks in the U.S. manufacturing sector. Our measure of volatility is the variation in Revenue Total Factor Productivity which is not explained by either industry- or economy-wide factors, or by establishments' characteristics. Consistent...