This paper argues that the balance of power between producers and retailersdepends on the relative degrees of differentiation at the two levels of thevertical structure. We propose an extension of Hotelling’s model in whichtwo producers, competing in prices with horizontally differentiatedproducts, face two horizontally differentiated retailers also competing inprices. We study the setting of producers’ and retailers’ margins. We showthat when retailers are more differentiated than producers, they dominatethe relationship and their margin is higher than producers’.