condemnation of this practice has been the court's belief in what has come to be known as the "leverage theory" of tying: that is … power to foreclose sales in, and thereby monopolize, a second market. In recent years, however, the leverage theory has come … used by the critics of the leverage theory which all assume that the tied good market has a competitive, constant returns …

consistent with the theory. We find that retailers are more likely to carry a store brand in a category if the share of the …