In the economic modeling of bargaining, outside options have often been naively treated by taking them as the disagreement payoffs in an application of the Nash bargaining solution. This paper contrasts this method of predicting outcomes with that obtained from an analysis of optimal strategic...

Models of (horizontal) product differentiation generally admit many equilibria. These include concentrated equilibria, in which few firms each offer many products, and fragmented equilibria, in which many firms each offer one product. Since these outcomes depend in a delicate way on features of...