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...

Historically, when an economy emerges from recession, employment grows with, or soon after, the resumption of GDP growth. However, following the two most recent recessions in the United States, employment growth has lagged the recovery in GDP by several quarters, a phenomenon thathas been termed...

We study a competitive model in which managers differ in ability and choose unobservable effort. Each firm chooses its size, how able a manager is to hire, and managerial compensation. The model can be considered an amalgam of agency and Superstars, where optimizing incentives enhances the...