Following the model-based approach of Ellison and Glaeser (1997), we develop a framework to test for the link between concentration, spatial clustering and the size of plants. Concentration is an a-spatial concept of variability that can be measured with the standard locational Gini or the more...

Using a matched employer-employee database for Italy we look at the spatial distribution of wages across provinces. This rich database allows us to contribute at opening the black box of agglomeration economies exploiting the micro dimension of the interaction among economic agents, both...

Equilibria and optima generally differ in imperfectly competitive markets. While this is well understood theoretically, it is unclear how large the welfare distortions are in the aggregate economy. Do they matter quantitatively? To answer this question, we develop a multi-sector monopolistic...

We characterize the equilibrium and optimal resource allocations in a general equilibrium model of monopolistic competition with multiple asymmetric sectors and heterogeneous firms. We first derive general results for additively separable preferences and general productivity distributions, and...