We study the principal-agent problem when there is nominal risk. We find that when nominal data are gathered with delay, fully indexed contracts are not time consistent, not renegociation proof.

We model research as a signal on an unknown parameter of a technology.

This a one-agent model of learning by doing and technology choice. The more the agent uses a technology, the better he learns its parameters, and the more productive he gets. This expertise is a form of human capital.

People at the top of an occupational ladder earn more partly because they have spent time on lower rungs, where they have learned something. But what precisely do they learn? There are two contrasting views: First, the "Bandit" model assumes that people are different, that experience reveals...

Technological progress comes in waves. The birth of information technology (IT) may herald the start of a Third Industrial Revolution. This paper argues that (a) the market declined in the late 1960s because it felt that the old technologies either had lost their momentum or would give way to...