Incentives for sabotage in vertically related industries

We show that the incentives of a vertically integrated supplier to "sabotage" the activities of downstream rivals can vary with both the type of sabotage and the nature of downstream competition. Cost-increasing sabotage is typically profitable under both Cournot and Bertrand competition. In contrast, demand-reducing sabotage is often profitable under Cournot competition, but unprofitable under Bertrand competition. Incentives for sabotage can vary non-monotonically with the degree of product differentiation.