The world is replete with spatial frictions. Shipping goods across cities entails trade frictions. Commuting within cities causes urban frictions. How important are these frictions in shaping the spatial economy? We develop and quantify a novel framework to address this question at three...

We analyze the equilibrium and the optimal resource allocations in a monocentric city undermonopolistic competition. Unlike the constant elasticity of substitution (CES) case, wherethe equilibrium markups are independent of the city size, we present a variable elasticity ofsubstitution (VES)...

This chapter surveys recent developments in agglomeration theory within a unifying framework. We highlight how locational fundamentals, agglomeration economies, the spatial sorting of heterogeneous agents, and selection effects affect the size, productivity, composition, and inequality of...