More rapid diffusion of science increases technological opportunity and innovation. To measure the diffusion of science, we use the lag between citing and cited scientific papers. With data from 1981 to 1999, the lag averages 6 years, increases with citation delay, and decreases with firm...

This paper considers research performance of U.S. universities for eight science fields. At the aggregate level we find that research output follows a constant returns to scale process. However, for individual universities we find evidence of diminishing returns. We offer two explanations for...

This paper explores the effect of research and development (R&D) and capital on factor intensity and skill bias in a sample of manufacturing plants. Firm and industry R&D as well as plant level capital increase the factor intensity of labor over materials. In contrast, skill bias originates in...

This paper studies the influence of R&D in the U.S. federal laboratory system, the world's largest, on firm research. Our results are based on a sample of 220 industrial research laboratories that work with a variety of federal laboratories and agencies and are owned by 115 firms in the...

This paper studies geographic localization of academic and industrial knowledge spillovers. Using data on US research and development laboratories that quantify spatial aspects of learning about universities and firms as well as the locations of closely affiliated universities and firms, I find...

We find that the effects of parent firm R&D on plant-level productivity are diminished by both the geographic and technological distance between the research lab and the plants; that productivity appears to depend on R&D per plant rather than on the total amount; and that spillovers from...