On vertical mergers and their competitive effects

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 an equilibrium theory of vertical merger that incorporates these additional strategic considerations. Under fairly general conditions, a vertical merger will result in both efficiency gains and a collusive effect. The competitive effects of a vertical merger depend on the cost of switching suppliers and the degree of downstream product differentiation.