A large literature has shown that geographic frictions reduce trade, but has not clarified precisely why. We provide insights into why such frictions matter by examining which parts of trade these frictions reduce most. Using data that tracks manufacturers' shipments within the United States on...

Wolf (2000) demonstrates that trade within the U.S. appears substantially impeded by state borders. We revisit this finding with improved data. We show that much intra-national home bias can be explained by wholesaling activity. Shipments by wholesalers are much more localized within states than...

We show that 'home bias' in trade patterns will arise endogenously due to the co-location decisions of intermediate and final goods producers. Our model identifies four implications of home bias arising out of specialized industrial demands. Regions absorb different bundles of goods. Buyers and...