Historical Changes in the Demographics of Inventors in the United States

Abstract

Who invents? This is a central question to understanding possible barriers to entry in the innovation process. To address it, we match the Annual Report of the Commissioner of Patents from 1870 to 1940 to the corresponding U.S. Federal Population Censuses. This matching procedure provides a rich set of demographic information on a comprehensive set of inventors. We first document that patentees over this seventy year period are more likely to be older, white, male and to be living in a state other than the one in which they were born. These patterns are very persistent over space and time. We then attempt to identify correlates of the demographics of patentees focusing on county-level economic and demographic characteristics. Beyond the most obvious, such as the fraction of a particular demographic group in that county, very little explains differences in the demographics of inventors across counties. We then examine two historical institutions that differentially affected particular demographic groups. For blacks, we consider historically black colleges and universities (HBCUs) and for women, state-level extension of the franchise. We find some evidence that HBCUs differentially increased black patenting rates while the extension of the franchise did not seem to have an effect for the representation of women amongst inventors.

Keywords: Historical US, Patents, Inventors, Demographics, Migration

JEL Classification: O31, O40, N11, N12