The paper applies Ricardo's principle of comparative advantage to analyze the substitutability between types of labor. The problem of having to classify labor in a small number of types in e.g. standard CES models are avoided by applying a continuum of worker and job types, where better skilled...

In this paper we derive a structural measure for labor market density based on the Ellison and Glasear (1997) "Index for industry concentration". This labor market density measure serves as a proxy for the number of workers that can reach a certain work area within a reasonal amount of traveling...