How do regions acquire the knowledge they need to diversify their economic activities? How does the migration of workers among firms and industries contribute to the diffusion of that knowledge? Here we measure the industry, occupation, and location specific knowledge carried by workers from one...

Ricardian theories of production often take the comparative advantage of locations in diff erent industries to be uncorrelated. They are seen as the outcome of the realization of a random extreme value distribution. These theories do not take a stance regarding the counterfactual or implied...