Cultural Diversity and Economic Growth: Evidence from the US during the Age of Mass Migration

We exploit the large inflow of immigrants to the US during the 1870-1920 period to examine the effects that changes in the cultural composition of the population of US counties had on output growth. We construct measures of fractionalization and polarization to distinguish between the different effects of cultural diversity. Our main finding is that increases in cultural fractionalization significantly increased output, while increases in cultural polarization significantly decreased output. We address the issue of identifying the causal effect of cultural diversity on output growth using the supply-push component of immigrant inflows as an instrumental variable.