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...

This paper describes flows of basic research through the U.S. economy and explores their implications for scientific output at the industry and field level. The time period is the late 20th century. This paper differs from others in its use of measures of science rather than technology. Together...

This article is a guide to the NBER-Rensselaer Scientific Papers Database, which includes more than 2.5 million scientific publications and over 21 million citations to those papers. The data cover an important sample of 110 top U.S. universities and 200 top U.S.-based Ramp;D-performing firms...

Due to improving information technology, the growing complexity of research problems, and policies designed to foster interdisciplinary research, the practice of science in the United States has undergone significant structural change. Using a sample of 110 top U.S. universities observed during...

This paper estimates science production functions for Ramp;D-performing firms in the United States using scientific papers as the measure of output, by analogy with patents. The underlying evidence covers 200 top U.S. Ramp;D firms during 1981-1999 as well as 110 top U.S. universities. We find...

The expansion of U.S. universities after World War II gained from the arrival of immigrant scientists and graduate students, the broadening of access to universities, and the development of military research and high technology industry. Since the 1980s, however, growth of scientific research in...

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 explores the implications of a simple model of learning and innovation by firms. In this model R&D spillovers are partly determined by firms, rather than by the given economic environment. According to this approach the full effect of spillovers on research productivity of firms...

The focus of this paper is the research performance of a system of universities and sciences. Using data from the US during the 1980s we study the relationship between research output and R&D in 8 different fields of science We begin at the field level by examining the time series behavior of...

This paper examines available U.S. data on academic R&D expenditures and the number of papers published and the number of citations to these papers as possible measures of `output' of this enterprise. We look at these numbers for science and engineering as a whole, for 5 selected major fields,...