Convergence in per capita income turns on whether technological knowledge spillovers are global or local. Global spillovers favor convergence, while a geographically limited scope of knowledge diffusion can lead to regional clusters of countries with persistently different levels of income per...

Convergence in per capita income across countries turns on whether technological knowledge spillover are global or local. This paper estimates the amount of spillover from R&D expenditures in major industrialized countries on a geographic basis. A new data set is used which encompasses most of...

This paper studies localization of academic and industrial knowledge spillovers. Using data on U.S. Research and Development laboratories, that quantify spatial aspects of learning about universities and firms as well as their locations, I find that academic spillovers are more localized than...

Patent data have been widely used in research on technological innovation to characterize firms' locations as well as the proximities among firms in knowledge space. Researchers could measure proximity among firms with a variety of measures based on patent class data, including Euclidean...

This paper uses wavelets to decompose each stock's trading-volume variance into frequency-specific components. We find that stocks dominated by short-run fluctuations in trading volume have abnormal returns that are 1% per month higher than otherwise similar stocks where short-run fluctuations...

Studies of firm-level data have shown that a firm's R&D and the R&D of other firms increase conventional factor productivity. We investigate these phenomena further by examining the relationship between plant-level productivity and firm-level R&D. We find that (1) the productivity-enhancing...

This paper estimates a dynamic structural model of discrete R&D investment and quantifies its cost and long-run benefit for German manufacturing firms. The dynamic model incorporates linkages between the firm's R&D choice, product and process innovations, and future productivity and profits. The...

This article investigates how a firm's financial strength affects its dynamic decision to invest in R&D. We estimate a dynamic model of R&D choice using data for German firms in high-tech manufacturing industries. The model incorporates a measure of the firm's financial strength, derived from...

This chapter reviews academic research on the connections between agglomeration and innovation. We first describe the conceptual distinctions between invention and innovation. We then describe how these factors are frequently measured in the data and some resulting empirical regularities....

We simultaneously assess the contributions to productivity of three sources of research and development spillovers: geographic, technology and product-market proximity. To do this, we construct a new measure of geographic proximity that is based on the distribution of a firm's inventor locations...