measures based on patents and their citations as indicators of technological output and information flow. This paper explores … the patents. Using a new and comprehensive dataset containing over 4800 U. S. Manufacturing firms and their patenting … activity for the past 30 years, we explore the contributions of R&D spending, patents, and citation-weighted patents to …

observed patent citations. A cohort of 1993 patentees were asked specifically about 2 patents that they had cited, and a third … for the cited patents than for the placebos. There is, however, a large amount of noise in citations data; it appears that …

firms typically protect the profits due to invention with a range of mechanisms, including patents, secrecy, lead time … advantages and the use of complementary marketing and manufacturing capabilities. Of these mechanisms, however, patents tend to … emphasized most heavily. A comparison of our results with the earlier survey findings of Levin et al. [1987] suggest that patents …

might enhance, or dampen, a firm's responsiveness to the availability of product patents. The picture presented here …

family size. The model is estimated for four technology areas using a sample of about 8000 U.S. patents applied for during …