We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation--in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to...

In this paper, I develop a model to analyze how skill premia differ over time and across countries, and use this model to study the impact of international trade on wage inequality. Skill premia are determined by technology and the relative supply of skills. An increase in the relative supply of...

This paper develops the thesis that credit market frictions may be an important contributor to high unemployment in Europe. When a change in the technological regime necessitates the creation of new firms, this can happen relatively rapidly in the U.S. where credit markets function efficiently....

An inventor's own knowledge is a key input in the innovation process. This knowledge can be built by interacting with and learning from others. This paper uses a new large-scale panel dataset on European inventors matched to their employers and patents. We document key empirical facts on...