Legal and illegal markets often coexist. In theory, marginal legalization can either substitute for the remaining parallel market, or complement it via scale effects. I study migrants crossing without prior authorization at the US southwest border, where large-scale unlawful crossing coexists...

This paper provides one of the first estimates of elasticities of substitution across suppliers within the same product. This paper estimates these elasticities using new real-time administrative tax data on firm-to-firm transactions, with product-level prices and quantities, leveraging...