Qihong Liu

Is the Effect of Competition on Price Dispersion Non-Monotonic? Evidence from the U.S. Airline Industry

We investigate the effect of competition on price dispersion in the airline industry. Using panel data from 1993 to 2008, we find a nonmonotonic effect of competition on price dispersion. An increase in competition is associated with greater price dispersion in concentrated markets but with less price dispersion in competitive markets—an inverse-U relationship. Our empirical findings are consistent with an oligopolistic second-degree price discrimination model and encompass contradictory findings in the literature.

Third-Degree Price Discrimination

This lecture deals with third-degree price discrimination in both monopolistic and oligopolistic markets. The classical monopoly paradigm serves as a benchmark. Next, we move to an oligopoly setting, first with best-response symmetry, then with best-response asymmetry. We end with behavior-based price discrimination. This lecture targets advanced undergraduate and graduate students.

Pricing-to-Market: Price Discrimination or Product Differentiation?

We employ a vertical differentiation model to examine the potential bias in pricing-to-market results when using export unit values aggregating differentiated products. Our results show that: (i) false evidence of pricing-to-market is always found when using unit values, whether the law of one price holds or not; and (ii) the size of the bias increases with the level of product differentiation. Our simulation results support those conceptual findings. Thus, some of the positive pricing-to-market results in the literature could be an artifact of the product heterogeneity embodied in unit values rather than evidence of imperfect competition.

Loyalty Rewards Facilitate Tacit Collusion

Using a dynamic overlapping-generations model, we show that loyalty rewards robustly facilitate tacit collusion. We compare the sustainability of tacit collusion when uniform prices are used, when loyal customers are rewarded without using commitment, and when loyalty rewards are implemented by committing to offering customers either lower fixed repeat-purchase prices or fixed repeat-purchase discounts. We find that, relative to uniform prices, rewarding loyalty without using commitment on the equilibrium path makes tacit collusion easier to sustain, because a deviating firm is unable to steal one period of industry profit before losing all future profits. When loyalty rewards are offered by firms committing to repeat-purchase prices, collusion is even easier to sustain, since a deviating firm cannot renege on its discounted price for repeat-purchase customers. When firms commit to repeat-purchase discounts, they also commit to lowering the price for their repeat-purchase customers if they undercut the regular price, rendering tacit collusion to be even more readily sustainable. Our results hold whether products are homogeneous or horizontally differentiated as in a Hotelling model.

Reverse Pricing and Revenue Sharing in a Vertical Market

Advancing in information technology has empowered firms with unprecedented flexibility when interacting with each other. We compare welfare results in a vertical market (e.g., manufacturers and retailers) for several types of pricing strategies depending upon the following: (1) which side (retailers or manufacturers) chooses retail prices; and (2) whether there is revenue sharing or linear pricing between the two sides. Our results are as follows. Under revenue sharing, retail prices (and thus industry profits) are higher if and only if they are chosen by the side featuring less competition. Under linear pricing, however, retail prices are higher if they are chosen by the side featuring more competition (for linear demand functions). Relative to linear pricing, revenue sharing always leads to lower retail prices, higher consumer surplus and social surplus. However, the comparison on industry profits depends on the demand elasticity ratios. Revenue sharing raises industry profits when the elasticity ratios are small, but the results are reversed when the elasticity ratios are large. Copyright

THE EFFECT OF MOST‐FAVORED CUSTOMER CLAUSES ON PRICES*

We study the effects of introducing a Most-Favored Customer (MFC) clause on price competition among major consumer electronics retailers. Our data spans the periods before and after the introduction of an MFC clause by Best Buy, which occurred between April 1, 2003 and March 31, 2004. After controlling for various factors (including product life-cycle and seasonality effects), we find that, on average, Best Buy lowered its prices by 1.6% after introducing the MFC clause. Its competitors responded by cutting prices further: Buy.com by 3.5%, Circuit City by 2.2%, CompUSA by 3.2%, and Sears by 0.4%. Our empirical results are robust to a variety of measures and estimation methods. We conclude that Best Buys MFC adoption reduced prices in the consumer electronics retail industry.

Tacit Collusion with Low-Price Guarantees

Existing studies on low‐price guarantees (LPGs) typically employ static models and the results are sensitive to modeling assumptions such as the type of guarantees, hassle costs and consumer heterogeneity. In contrast, we employ a fully dynamic model and show that LPGs robustly facilitate tacit collusion, by reducing a deviating firms immediate deviation profit. This difference of results is because in a static model, any equilibrium has to be immune from any deviation, including infinitesimal deviation. In a dynamic model, however, one can ignore infinitesimal deviations since firms never have an incentive for such deviations.

Customer Poaching and Coupon Trading

Abstract The price discrimination literature typically makes the assumption of no consumer arbitrage. This assumption is increasingly violated in the digital economy, where coupons are traded with increased frequency online. In this paper, we analyze the welfare impacts of coupon trading using a modified Hotelling model where firms send coupons to poach each other’s loyal customers. The possibility of coupon trading renders this important instrument for price discrimination less effective. Moreover, coupon distribution has unintended consequences when coupon traders sell coupons back to a firm’s loyal customers. Consequently, coupon trading may reduce firms’ incentive to distribute coupons, leading to higher prices and profits. We find that, an increase in coupon distribution cost lowers promotion frequency but raises promotion depth, and an increase in the fraction of coupon traders lowers both promotion frequency and promotion depth.

Price Discrimination with Varying Qualities of Information

Advances in information technology have greatly enhanced firms’ ability to collect, market and utilize consumer information. As the market for consumer information expands rapidly, businesses are armed with unprecedented means to target any group of consumers they desire. This has important and far-reaching impacts on consumer welfare. In this paper we analyze the welfare impacts of price discrimination facilitated by increasing qualities of consumer information. We employ a two-dimensional spatial differentiation model where consumer information is available on one dimension, and better information leads to more refined price discrimination. We find that as information quality improves, equilibrium prices and profits monotonically increase while consumer surplus and social surplus monotonically decrease. Price discrimination has a reduced demand elasticity effect which becomes stronger when consumer information becomes more precise. Our results suggest that regulators need to pay more attention to the potential damage to consumer welfare by the increasing collection and utilization of consumer information. We also endogenize firms’ information acquisition decisions.

When Do Firms Offer Higher Product Quality? Evidence from the Allocation of Inflight Amenities

This study examines when firms offer higher product quality. We measure product quality by examining four different inflight amenities provided by airlines: Wi-Fi, seat size, entertainment, and seat power. Using daily flight level data for over 800 routes and spanning nine weeks in third quarter of 2015 we observe that carriers were actively retrofitting aircraft to expand their inflight amenity offerings. We find significantly lower product quality (Wi-Fi, entertainment, and power) on more concentrated routes. While considerable research has been done on airline pricing, less well known is how airlines pursue other revenue streams from ancillary services. Recent work by Brueckner et al. (2015) explores the role of baggage fees in airline pricing. We examine additional revenue streams provided by Wi-Fi and entertainment inflight amenities. We find that carriers are lowering the posted base ticket prices on routes with Wi-Fi and entertainment and then charging passengers for using these amenities. The IV price estimates reveal that magnitude of the posted fare reduction is larger than the additional revenue generated from the inflight amenity.