We consider differentiated duopolists facing symmetric linear demands and using Cobb-Douglas technologies with two inputs: a monopolized input and a competitively supplied input. Unlike with fixed-proportions technologies, a merger between the input monopolist and either firm can reduce welfare....

We analyze the competitive effects of backward vertical integration when firms exert market power upstream and compete à la Cournot downstream. Contrasting with previous literature, a small degree of vertical integration is always procompetitive because efficiency gains dominate foreclosure...