We show a causal impact of immigration on innovation and dynamism in US counties. To identify the causal impact of immigration, we use 130 years of detailed data on migrations from foreign countries to US counties to isolate quasi-random variation in the ancestry composition of US counties that...

We study how decades-long exposure to individuals of a given foreign descent shapes natives' attitudes and behavior toward that group, exploiting plausibly exogenous shocks to the ancestral composition of US counties. We combine several existing large-scale surveys, cross-county data on implicit...

We show a causal impact of immigration on innovation and dynamism in US counties. To identify the causal impact of immigration, we use 130 years of detailed data on migrations from foreign countries to US counties to isolate quasi-random variation in the ancestry composition of US counties that...