The foreclosure argument for exclusive dealing: The case of differentiated retailers

I analyze a cooperative characteristic-form game between two differentiated producers and a downstream retail sector. When there is a single downstream retailer, the game always has a nonempty Core, involving the retailer being a common dealer. Each producer can at most earn his increment to the collusive industry profit. This result is similar to what is obtained in the literature in an extensive-form noncooperative formulation of the game. When there are two differentiated downstream retailers, the Core is empty when products and retailers are too homogeneous. For sufficient product and retailer differentiation, the Core is nonempty. In these cases the retailers are always common dealers for both products.