608. Einer Elhauge, Loyalty Discounts and Naked Exclusion; subsequently published as “How Loyalty Discounts Can Perversely Discourage Discounting” in Journal of Competition Law & Economics, Vol. 5, 2009, 189.
Abstract: Loyalty discounts are agreements to sell at a lower price to buyers who buy all or most of their purchases from the seller. This article proves that loyalty discounts create anticompetitive effects, not only because they can impair rival efficiency, but because loyalty discounts perversely discourage discounting even when they have no effect on rival efficiency. The essential reason, missed in prior work, is that firms using loyalty discounts have less incentive to compete for free buyers, because any price reduction to win sales to free buyers will, given the loyalty discount, also lower prices to loyal buyers. This in turn reduces the incentive of rivals to cut prices, because there will exist an above-cost price that rivals can charge to free buyers without being undercut by the firm using loyalty discounts. These anticompetitive effects occur even if buyers can breach or terminate commitments, and even if the loyalty conditions require no contractual commitments and less than 100% loyalty. Further, I prove that these anticompetitive effects are exacerbated if multiple sellers use loyalty discounts. None of the results depend on switching costs, market differentiation, imperfect competition, or the loyalty discount bundling contestable and incontestable demand. Contrary to commonly held views, I prove these anticompetitive effects exist even when: (1) the price with the loyalty discount is above cost, (2) the rival has higher costs than the firm using loyalty discounts, (3) the rival prices above its own costs, (4) buyers voluntarily agree to the conditions, and (5) the discount and foreclosure levels are low. I derive formulas for calculating the inflated price levels in each situation.