Tying and Bundling in a Nearly Contestable Market

This paper presents a model of bundling and tying when the threat of entry provides the primary competitive constraint, but entrants have a disadvantage with respect to the incumbent, i.e., in a, “nearly contestable,” market. The entrant’s disadvantage can be with respect to marginal costs, the fixed cost of a good, or the fixed cost of an offering (which can be interpreted as a product differentiation advantage). The incumbent’s profits depend on both the nature of its cost advantage and the set of offerings. With an advantage in the fixed cost of an offering, the incumbent prefers mixed bundling if it is sustainable. With a marginal cost advantage, the incumbent prefers pure bundling, in which all customers buy both components. While the latter result might appear to formalize a commonly-alleged rationale for tying, the practice can be a Pareto improvement over mixed bundling and can cause total consumer surplus to increase relative to only selling the products separately. Mixed bundling can lower consumer surplus and be a form of product proliferation.