A Theory Appendix

This web appendix contains the technical derivations for the theoretical results in the paper and reports additional empirical results and information concerning the data. Section A provides a full characterization of the structural model and discusses the relationship between the reduced-form coefficients and structural parameters. Section B deals with the econometric inference, including the derivations of the likelihood function, the set up of the GMM objective, and handling of measurement error. Section C discusses the data sources and definitions, while the detailed lists of industries and occupations used in the analysis can be found in a separate web supplement.1 Section D contains additional empirical results and robustness checks referred to in the paper. (3) (6