We report a puzzling pair of facts concerning the organization of science. The concentration of research output is declining at the department level but increasing at the individual level. For example, in evolutionary biology, over the period 1980 to 2000, the fraction of citation-weighted...

We explore the determinants of research specialization across countries and its consequences for relative wages. Using a dynamic Ricardian model we examine the effects of faster international technology diffusion and lower trade barriers on the incentive to innovate. In the absence of any...

The recruitment of foreign scientists enhances US science through an expanded workforce but could also cause harm by displacing better connected domestic scientists, thereby reducing localized knowledge spillovers. We develop a model in which a sufficient condition for the absence of overall...

European countries do less research than Japan and the United States. We use a quantitative multi-country growth model to ask: (i) Why is this so? (ii) Would there be any benefit to expanding research in Europe? (iii) What would various European research promotion policies do? We find that (i)...

We develop a parsimonious model of innovating firms rich enough to confront firm-level evidence. It captures the dynamic behavior of individual heterogenous firms, describes the evolution of an industry with simultaneous entry and exit, and delivers a general equilibrium model of technological...

In this chapter we draw from existing literature and a range of statistics to describe economic, entrepreneurial and innovative activities in the transportation and warehousing sector of the U.S. economy. We suggest multiple avenues for future work, and argue for more research on the role of...