It is well known that vertical integration can change the pricing incentive of an upstream producer. However, it has not been noticed that vertical integration may also change the pricing incentive of a downstream producer and the incentive of a competitor in choosing input suppliers. I develop...

A vertical merger between a firm and an input supplier to that firm can generate efficiencies by eliminating double marginalization or alleviating other contracting inefficiencies. However, when the supplier also sells to that firm's rivals, a key antitrust concern is input foreclosure: the...

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....

Economists widely agree that, absent sufficient efficiencies or other offsetting factors, mergers that increase concentration substantially are likely to be anticompetitive. Further, holding everything else equal, the magnitude of anticompetitive effects tends to be larger, the larger is the...