Immigration, local crowd-out and undercoverage bias

Revised May 2020. Revised January 2021. Using decadal census data since 1960, I cannot reject the hypothesis that new immigrants crowd out existing residents from US commuting zones and states one-for-one. My estimate is precise and robust to numerous specifications, as well as accounting for local dynamics; and I show how it can be reconciled with apparently conflicting results in the literature. Exploiting my model's structure, I attribute 30% of the observed effect to mismeasurement, specifically undercoverage of immigrants. Based on a remarkably simple decomposition, I show that population mobility accounts for 90% of local adjustment, and labor demand the remainder. These results have important methodological implications for the estimation of immigration effects.