The division of labor between and within countries is driven by two fundamental forces, comparative advantage and increasing returns. We set up a simple Ricardian model with a Marshallian input sharing mechanism to study their interplay. The key insight that emerges is that the interaction...

A recent strand of the economic literature has emphasised the role of services, and in particular knowledge-intensive business services (KIBS), as a primary source of knowledge creation and diffusion. Since this transferring process often occurs through strong face-to-face interactions, the role...

Larger cities typically give rise to two opposite effects: tougher competition among firms and higher production costs. Using an urban model with substitutability of production factors and pro-competitive effects, I study the response of the market outcome to city size, land-use regulations, and...