Research on the labor market impact of immigration typically relies on a single-good model of production with separable capital. This article discusses theory and evidence that suggest that this standard model is too simple to capture the labor market impact of immigration. A reasonable level of...

This paper estimates the elasticity of substitution between capital and skill using variation across U.S. counties in immigration-induced skill-mix changes between 1860 and 1930. We find that capital began as a q-complement for skilled and unskilled workers, and then dramatically increased its...