Essays in labour economics and innovation

This thesis consists of three chapters that examine how scientists and inventors shape the rate, direction, and diffusion of science and innovation. Chapter 1 studies the consequences of the Black-white gap among scientists and inventors. Using data on US patents, medical research articles, and clinical trials linked to the racial distribution of last names in the US population, I find that the racial and ethnic composition of scientists has important implications for the direction and the rate of medical research and innovation. Chapter 2 studies how societies react to adverse events. Following the 1918 Influenza Pandemic in the US, we document an increase in country-level religiosity and innovation. Within counties, individuals from more religious backgrounds become more religious, while those from less religious backgrounds are more likely to pursue scientific occupations. Facing adversity widens the distance in religiosity between science-oriented individuals and the rest of the population, and it increases the polarization of religious beliefs. Chapter 3 studies how human mobility affects the production and diffusion of innovation. Using full-count census data for the UK and the US and newly-digitized UK patent data, we document that out-migration promotes the diffusion of new technologies from the country of destination to the country of origin of migrants. While physical return migration is an important driver of this “return innovation” effect, the interactions between emigrants and their origin communities promote technology diffusion even without return migration.