The purpose of this paper is to present and estimate a model which allows one to use the recently computerized U.S. Patent Office's data base to identify when and where changes in inventive output have occurred. The model assumes a firm which chooses a research strategy to maximize the expected...

It is known that innovations in the market value of manufacturing firms and their RhD expenditures are related (Pakes (1985) and Mairesse and Siu (1984)). This could be due to shifts in the demand for the output of a particular firm, to shifts in the technological opportunities available to the...

This paper summarizes a number of studies which use patent data to examine different aspects of technological change. It describes our firm level data set construction effort; reports on the relationship between RLD expenditures and the level of patenting; analyzes the relationship between...

This is a first report from a larger study of inventive activity of U.S. firms and some of its consequences. It reports on the relationship between patents applied for and R&D expenditures based on data for 121 large corporations covering the 1968-1975 period. The main conclusion is that there...