We examine geographic concentration, agglomeration, and co-location of university research and industrial R&D in three technological areas: medical imaging, neural networks, and signal processing. Using data on scientific publications and patents as indicators of university research and...

We develop a model of information exchange through communication and investigate its implications for information aggregation in large societies. An underlying state determines payoffs from different actions. Agents decide which others to form a costly communication link with incurring the...

It concludes by constructing a simple model in which knowledge flows slowly across national borders but moves easily within borders. We show there is a leadership-followership equilibrium, in which some countries are leaders, others are followers. Contrary to Solow's analysis, there need not be...

Because of their more limited inequality and more comprehensive social welfare systems, many perceive average welfare to be higher in Scandinavian societies than in the United States. Why then does the United States not adopt Scandinavian-style institutions? More generally, in an interdependent...

We document that the percentage of all U.S. assets that are "safe" has remained stable at about 33 percent since 1952. This stable ratio is a rare example of calm in a rapidly changing financial world. Over the same time period, the ratio of U.S. assets to GDP has increased by a factor of 2.5,...

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...

In the centuries leading up to the Industrial Revolution, Western Europe gradually pulled ahead of other world regions in terms of technological creativity, population growth, and income per capita. We argue that superior institutions for the creation and dissemination of productive knowledge...

We examine the role of spillover learning in shaping the value of exploratory versus incremental R&D. Using data from drug development, we show that novel drug candidates generate more knowledge spillovers than incremental ones. Despite being less likely to reach regulatory approval, they are...