I discuss the concept and empirical importance of international technology diffusion from the point of view of recent work on endogenous technological change. In this literature, technology is viewed as technological knowledge. I first review the major concepts, and how international technology...

Interpreting individual heterogeneity in terms of probability theory has proved powerful in connecting behaviour at the individual and aggregate levels. Returning to Ricardo's focus on comparative efficiency as a basis for international trade, much recent quantitative equilibrium modeling of the...

This paper and its companion study, Fehr, Jokisch, and Kotlikoff (2004), develop a three-region dynamic general equilibrium life-cycle model to analyze general and skill-specific immigration policy during the demographic transition. The three regions are the U.S., Japan, and the EU. Immigration...

How do communication costs affect the production of new ideas and inventions? To answer this question, we study the introduction of the Uniform Penny Post in Great Britain in 1840. This reform replaced the previous system of expensive distance-based postage fees with a uniform low rate of one...

This paper uses a large language model to develop an ex-ante measure of the commercial potential of scientific findings. In addition to validating the measure against the typical holdout sample, we validate it externally against 1.) the progression of scientific findings through a major...

Understanding factors affecting the direction of innovation is a central aim of research in the economics of innovation. Progress on this topic has been inhibited by difficulties in measuring distance and movement in knowledge space. We describe a methodology that infers the mapping of the...