Preemptive Spacing with Vertical Differentiation When Input Quality is of Inelastic Supply

This paper examines a model of vertical differentiation in which an incumbent engages in preemptive spacing to prevent entry. Input quality is of fixed supply, and the incumbent prevents high-end entry by producing a product with all the quality available. It also commits to the production of a minimum-quality product to deter low-end entry. There is no entry in equilibrium, and the incumbent monopolist chooses to sell only its high-quality product. Commitment to the production of the minimum-quality product is used merely as a credible threat to vigorously compete should an entrant also produce a minimum-quality product