Konstantinos Serfes

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.

A Location Model With Preference for Variety

We propose a new location model where consumers are allowed to make multiple purchases (i.e., one unit from each firm). This model fits many markets (e.g. newspapers, credit cards, scholarly journals, subscriptions to TV channels, etc.) better than existing models. A common feature of these markets is that some consumers are loyal to one brand, while others consume more than one product. Our model yields predictions consistent with this observation. Moreover, it restores Hotellings Principle of Minimum Differentiation, by generating an equilibrium in pure strategies and with a linear transportation cost, where firms are located at the center and charge prices above marginal cost

Endogenous Matching in a Market with Heterogeneous Principals and Agents

We employ the assignment game of Shapley and Shubik (Int J Game Theory 1:111–130, 1972) to study the endogenous matching patterns in a market that consists of heterogenous principals and agents. We show that, in general, the equilibrium matching is non-assortative. We then characterize the equilibrium relationship between risk and performance pay and risk and fixed compensation. This is the first paper that characterizes the equilibrium matching, to its fullest possible extent, building on the Holmstrom and Milgrom (Econometrica 55:303–328, 1987) principal-agent model. This model has been used extensively in the empirical literature and therefore we hope that our results will be of value to empirical researchers who wish to study a principal-agent market.

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.

Minimum quality standard regulation under imperfect quality observability

Minimum quality standards (MQS) constitute an important regulatory tool that can be used to raise product qualities, to benefit consumers and to increase market participation. One of the main assumptions in the existing literature is that firms must comply with standards. Nevertheless, in many industries, and in particular the service industry, quality observability and enforceability are not perfect. Some low quality firms do not comply with standards. What are the welfare implications of an MQS regulation in such an environment? We develop a price competition model of vertical differentiation that accounts for these empirical observations. Contrary to well-established results in the literature, MQS can increase quality disparity between firms and raise hedonic prices. Some consumers get hurt and market participation decreases.

Estimating the Effects of a la Carte Pricing: The Case of Cable Television

Consumer groups have been complaining about rising cable television prices. One proposed solution to combat these rising rates is to allow consumers to choose cable channels on a channel-by-channel basis (so-called a la carte offerings). In this paper, we explore the likely implications of a government regulation that would require cable and satellite operators to offer television channels on an a la carte basis. Using a policy simulation in which we explicitly model the strategic interaction between cable providers and programming networks, we find that consumer welfare goes up unambiguously under a la carte pricing. The expected monthly expenditure per household falls by approximately 15 to 20 percent and consumer welfare increases considerably. On the other hand, even ignoring the (technological) fixed costs associated with compliance with an a la carte regulation, we find that cable operator profits will fall. Finally, as we might expect, some programming networks benefit from a la carte pricing, while others are harmed (due, at least partially, to increased competition among close substitutes).

Location Decisions of Competing Networks

Early entrants in markets with network effects usually occupy a “central location” and serve agents with “intermediate tastes,” whereas later entrants are niche players. Why would the first entrant choose to become a “general” network, given that later entrants will not have enough room for differentiation, resulting in a more intense competition for market share? In a Hotelling model with two rival networks, we show that for intermediate values of the network externality parameter the location equilibrium is indeed asymmetric: the first entrant locates at the center whereas the second entrant chooses an extreme (niche) location.

The Comparison of Ad Valorem and Specific Taxation Under Uncertainty

The comparison between specific (per unit) and ad valorem (percentage) taxation has been one of the oldest issues in public finance. In Cournot markets, with deterministic costs structures, conventional wisdom has it that ad valorem taxation tax-revenue dominates specific. It is shown that in the presence of uncertainty, regarding firms’ cost structures, and under reasonable conditions, the conventional wisdom might not hold. The implication of this, from a policy perspective, is that the precise evaluation of the two types of taxation requires an explicit consideration of cost uncertainty.

Non-myopic learning in differential information economies: the core

We study the process of learning in a differential information economy, with a continuum of states of nature that follow a Markov process. The economy extends over an infinite number of periods and we assume that the agents behave non-myopically, i.e., they discount the future. We adopt a new equilibrium concept, the non-myopic core. A realized agreement in each period generates information that changes the underlying structure in the economy. The results we obtain serve as an extension to the results in Koutsougeras and Yannelis (1999) in a setting where agents behave non-myopically. In particular, we examine the following two questions: 1) If we have a sequence of allocations that are in an approximate non-myopic core (we allow for bounded rationality), is it possible to find a subsequence that converges to a non-myopic core allocation in a limit full information economy? 2) Given a non-myopic core allocation in a limit full information economy can we find a sequence of approximate non-myopic core allocations that converges to that allocation?

Intertemporal discounting and tenurial contracts

A simple two-period model, without uncertainty and strategic complementarity in the labor market or asymmetric information of any kind, is employed to study the nature of contracts signed between a landlord and a tenant in a rural economy. The paper provides conditions under which different types of contracts may prevail. q 2001 Elsevier Science B.V. All rights reserved.