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...

This paper develops a micro-founded city systems model with an endogenous number of cities to explore whether local governments establish the optimal city size when production processes involve environmental pollution. Our analysis delivers two key insights. First, if an optimal scheme to...