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 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...

We compare the geographic location of patent citations to those of the cited patents, as evidence of the extent to which knowledge spillovers are geographically localized. We find that citations to U.S. patents are more likely to come from the U.S., and more likely to come from the same state...

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...

Using a unique firm-level dataset from China's quot;Silicon Valley,quot; we investigate how multinational enterprises (MNEs) affect local entrepreneurship and Ramp;D activities upon entry. We find that Ramp;D activities of MNEs in an industry stimulate entry of domestic firms into the same...

In science as well as technology, the diffusion of new ideas influences innovation and productive efficiency. With this as motivation we use citations to scientific papers to measure the diffusion of science through the U.S. economy. To indicate the speed of diffusion we rely primarily on the...

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...

A key decision in research is whether to try out new ideas or build on more established ideas. In this paper, we evaluate which type of work is more likely to spur further invention. When recent advances create superior opportunities for invention, their adoption as research inputs in the...

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...