Raising rivals' costs: The entry of an upstream monopolist into downstream markets

Abstract A regulated upstream monopolist provides an input to firms in a downstream market. If the monopolist enters the downstream market, a natural concern is that it will act so as to raise its downstream rivals' costs. An offsetting incentive is that a higher downstream price will reduce demand for the input, which reduces the monopolist's profit. Conditions under which one incentive dominates the other are derived. The monopolist may desire to lower its downstream rivals' costs rather than raise them. These findings suggest that regulatory policy towards such downstream entry should not focus exclusively on the ability to discriminate.