evidence on the role of these commuting flows in supporting such concentrations of economic activity. Steam railways … buildings in Greater London by 20 percent or more, and brings down commuting into the City of London from more than 370,000 to …

model that incorporates spatial linkages in goods markets (trade) and factor markets (commuting and migration). We show that … local employment elasticities differ substantially across U.S. counties and commuting zones in ways that are not well … explained by standard empirical controls but are captured by commuting measures. We provide independent evidence for these …