This paper evaluates the sources of transitory market power in the market for personal computer (PCs) during the late 1980s. Our analysis is motivated by the coexistence of low barriers to entry into the PC industry and high rates of innovative investment by a small number of PC manufacturers.

This paper studies the consequences of physician authority on pharmaceutical prescribing. Physicians engage in a costly process of "matching" patients to the drug which most suits their particular conditions and characteristics.

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,...

The steam engine is widely regarded as the icon of the Industrial Revolution and a prime example of a “General Purpose Technology,” and yet its contribution to growth is far from transparent. This paper examines the role that a particular innovative design in steam power, the Corliss engine,...

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 that, (1) Patets assigned to the same firm are more likely to cit each other, and come sooner that other citations; (2) patents in the same patent class...