An endogenous growth model is developed where each period firms invest in researching and developing new ideas. An idea increases a firm's productivity. By how much depends on how central the idea is to a firm's activity. Ideas can be bought and sold on a market for patents. A firm can sell an...

This paper studies the effect of top tax rates on inventors' mobility since 1977. We put special emphasis on”superstar" inventors, those with the most and most valuable patents. We use panel data on inventors from the United States and European Patent Offices to track inventors' locations over...

This paper sheds light on the questions, Why does knowledge spill over? and How does knowledge spill over? The answer to these questions lies in the incentives confronting scientists to appropriate the expected value of their knowledge considered in the context of their path-dependent career...

This paper analyzes the birth of the Encryption Software Industry (ESI), a new market niche in the software industry. This work will report the main facts of entry and exit process, focusing on firm post-entry performance, on the different phases of competition during the industry evolution, and...

This note expounds the abstract fundamentals of the appropriability problem, re-assessing insights from three classic contributions – those of Schumpeter, Arrow and Teece. Whereas the first two contributions were explicitly concerned with the implications of appropriability for society at...

Using the 2003 National Survey of College Graduates, I examine how immigrants perform relative to natives in activities likely to increase U.S. productivity, according to the type of visa on which they first entered the United States. Immigrants who first entered on a student/trainee visa or a...