Stiglitz, together with Avinash Dixit, created a tractable model of monopolistic competition that was an alternative to traditional perfect-competition models of general equilibrium. They showed that in the presence of increasing returns to scale, the entry of firms is socially too small. The model was extended to show that when consumers have a preference for diversity, entry can be socially too large. The modeling approach was used by Paul Krugman in his analysis of the non-comparative advantage trading patterns.
Stiglitz, together with Avinash Dixit, created a tractable model of monopolistic competition that was an alternative to traditional perfect-competition models of general equilibrium. They showed that in the presence of increasing returns to scale, the entry of firms is socially too small The model was extended to show that when consumers have a preference for diversity, entry can be socially too large. The modeling approach was used by Pa.ul Krugman in his analysis of the non-comparative advantage trading patterns.