We compare the geographic location of patent citations to those of the cited patents, as evidence of the extent to which knowledge spillovers are geographically localized. We find that citations to U.S. patents are more likely to come from the U.S., and more likely to come from the same state...

We explore the use of patent citations to measure the "basicness" and appropriability of inventions. We propose that the basicness of research underlying an invention can be characterized by the nature of the previous patents cited by an invention; that the basicness of research outcomes relates...

This paper explores changes in university patenting behavior between 1965 and 1988. We show that university patents have increased 15-fold while real university research spending almost tripled. The causes of this increase are unclear, but may include increased focus on commercially relevant...

This paper describes the database on U.S. patents that we have developed over the past decade, with the goal of making it widely accessible for research. We present main trends in U. S. patenting over the last 30 years, including a variety of original measures constructed with citation data,...

A survey of recent patentees was conducted to elicit their perceptions regarding the importance of their inventions, the extent of their communication with other inventors, and the relationship of both importance and communication to observed patent citations. A cohort of 1993 patentees were...

The extent to which new technological knowledge flows across institutional and national boundaries is a question of great importance for public policy and the modeling of economic growth. This paper develops a model of the process generating subsequent citations to patents as a lens for viewing...

This paper explores the patterns of citations among patents taken out by inventors in the U.S., the U.K., France, Germany and Japan. We find (1) patents assigned to the same firm are more likely to cite each other, and come sooner than other citations; (2) patents in the same patent class are...

As patent data become more available in machine-readable form, an increasing number of researchers have begun to use measures based on patents and their citations as indicators of technological output and information flow. This paper explores the economic meaning of these citation-based patent...

Much recent work in strategy and popular discussion suggests that an excessive focus on "managing the numbers" --delivering quarterly earnings at the expense of longer term investments--makes it difficult for firms to make the investments necessary to build competitive advantage. "Short termism"...

General Motors was once regarded as one of the best managed and most successful firms in the world, but between 1980 and 2009 its share of the US market fell from 62.6 to 19.8 percent, and in 2009 the firm went bankrupt. In this paper we argue that the conventional explanation for this decline -...