How is long run economic growth related to the endogenous diversity of knowledge? We formulate and study a microeconomic model of knowledge creation, through the interactions among a group of heterogeneous research and development (R&D) workers, embedded in a growth model to address this...

Zipf's law is one of the best-known empirical regularities of the city-size distribution. There is extensive research on the subject, where each city is treated symmetrically in terms of the cost of transactions with other cities. Recent developments in network theory facilitate the examination...

This paper demonstrates that a pollution tax with a fixed cost component may lead, by itself, to segregation between clean and dirty firms without heterogeneous preferences or increasing returns. We construct a simple model with two locations and two industries (clean and dirty) where pollution...

This paper presents a new framework for modeling the fine microstructure of knowledge creation dynamics. Our focus is on the creation of working nowledge used in innovation, for example, the knowledge used by a researcher in the economics profession. The framework has been developed to address...

We offer a guide to the recent literature on the problem of fair allocation, and we present various concepts that have been developed in this literature and the various economic environments in the context of which they have been analyzed.