How Social Structure Drives Innovation: Surname Diversity and Patents in U.S. History

Abstract

We show that innovation in U.S. counties from 1850 to 1940 was propelled by shifts in the local social structure, as captured using the diversity of surnames. Leveraging quasi-random variation in counties’ surnames—stemming from the interplay between historical fluctuations in immigration and local factors that attract immigrants—we find that more diverse social structures increased both the quantity and quality of patents, likely because they spurred interactions among individuals with different skills and perspectives. The results suggest that the free flow of information between diverse minds drives innovation and contributed to the emergence of the U.S. as a global innovation hub.