A fundamental question in monopolistic competition theory is whether the market allocates resources efficiently. This paper generalizes the Spence-Dixit-Stiglitz framework to heterogeneous firms, addressing when the market provides optimal quantities, variety and productivity. Under constant...

After some decades of relative oblivion, the interest in the optimality properties of monopolistic competition has recently re-emerged due to the availability of an appropriate and parsimonious framework to deal with firm heterogeneity. Within this framework we show that non-separable utility,...