ASYMMETRIC INFORMATION AND EXCHANGE OF INFORMATION ABOUT PRODUCT DIFFERENTIATION

We introduce asymmetric information about consumers’ transportation costs (i.e., the degree of product differentiation) in the model of Hotelling. When transportation costs are high, both firms have lower profits with asymmetric information than with perfect information. Contrarily, if transportation costs are low, both firms may prefer the asymmetric information scenario (the informed firm always prefers the informational advantage, while the uninformed firm may or may not prefer to remain uninformed). Information exchange is ex‐ante advantageous for both firms, but ex‐post damaging if transportation costs turn out to be low. If the information is unverifiable, the informed firm does not represent a reliable source of information, since it always prefers to announce that transportation costs are high and there is no contract that induces truthful revelation.     

ENTRY AND QUALITY SIGNALLING WHEN ONLY SOME CONSUMERS ARE INFORMED OF THE ENTRANT'S QUALITY

This paper focuses on competition between an incumbent and an entrant when only the entrant's quality is unknown to (some) consumers. The incumbent may or may not know the entrant's quality. The model reveals a separating equilibrium where the entrant's high price signals its high quality when the proportion of informed consumers is at some intermediate value. The case in which the incumbent knows the entrant's quality generates two additional equilibria. When the proportion of informed consumers is large enough, firms choose their prices as in the complete information case. The entrant's high price in combination with the incumbent's low price signals the entrant's high quality. When the proportion of informed consumers is at some intermediate value, the incumbent's high price signals the entrant's low quality, while its low price signals the entrant's high quality. Interestingly, we find that entry may be facilitated with informational product differentiation.     

THE EXISTENCE OF EQUILIBRIUM IN A DIFFERENTIATED DUOPOLY WITH NETWORK EXTERNALITIES*

The existence of a pure‐strategy subgame‐perfect equilibrium in qualities and prices is investigated in a duopoly model of vertical differentiation where quality improvements require a quadratic variable cost and network externalities operate. We show that there exists a parameter region where the incentive to predate at the quality stage prevents firms from reaching a pure‐strategy non‐cooperative equilibrium with prices above marginal costs. If network externalities are sufficiently large, a Bertrand equilibrium with zero profits may arise, although the amount of product differentiation is strictly positive.     

A note on welfare-improving ignorance about quality

Consider a monopolist that is selling a high quality product when the quality is unknown to a fraction of the consumers. If the quality cannot be signaled and the fraction is sufficiently large, then the monopolist will offer a low price to induce uninformed consumers to buy. If the fraction is sufficiently small, then uninformed consumers are irrelevant to its optimal price. If the uninformed consumers are priced out of the market as a result, then welfare can decrease. I am very grateful for the comments of two anonymous referees that have significantly improved this paper.     

The Influence of a Neighbouring Market on Product Qualities and Prices

This paper analyses a model of vertical product differentiation in which there is a primary market with two firms and a secondary market with no firms. Consumers in the secondary market incur a cost when purchasing the product from the primary market. The firms sequentially choose product quality and then simultaneously choose prices. Firm 1 always chooses the maximum quality, while firm 2's quality and the prices depend on the cost. Also, the cost determines which firm(s), if either, serves the secondary market. It is shown that the firms and the consumers of each market prefer different levels of costs.     

Price and information disclosure in the private art market: A signalling game

In this paper, we model private art market agents’ strategic interactions in presence of two types of asymmetric information, about artwork quality and buyer’s knowledge, assuming the seller does not know how informed is the buyer while the buyer does not know the quality of the artwork before purchase. If the seller can choose either a high or a low price and the buyer can signal his type to the seller, we identify the conditions for both equilibria with pooling buyer signalling strategy and with separating strategy, as well as conditions for equilibria where the seller fixes the price according to the actual quality and where he posts prices trying to take advantage of buyer’s limited information. Finally, we identify the condition for the emergence of a “counter-lemon” result, where low-quality artworks and uninformed collectors exit the market, suggesting that seller uncertainty does not directly benefit the buyers, but it can impact the quality traded in the market.     

Nesting Horizontal and Vertical Differentiation with Location Choices

This study solves a location‐then‐price game in which horizontal and vertical differentiation are combined using an asymmetric distribution of consumers’ taste. Boundary locations are robust when the taste disparity of the population is not large and out‐of‐market locations are not allowed. Firms may have incentives to move either inside or outside the market in other situations, so the equilibrium prices are never differentiated. The restrictions of vertical differentiation under this framework are further examined. A model with the entrance of a vertically differentiated product is also discussed.     

Rationing rule, imperfect information and equilibrium

Summary. The impact of imperfect information on the price setting behaviour of firms is analysed. Specifically, consumers support an information cost to become informed about prices. Firms are endowed with U-shaped average cost curves. If a firm does not supply more than its competitive supply as determined by its marginal cost schedule, then we show that the existence of a pure strategy equilibrium is conditional on the rationing rule employed. If uninformed consumers are served first then the monopoly price is the sole equilibrium whenever consumers' information costs are high enough. Otherwise, a pure strategy equilibrium fails to exist contrary to the results of Salop and Stiglitz (1977) or Braverman (1980) who implicitly suppose that firms supply all the demand at a given price. Received: May 17, 1999; revised version: September 15, 2000     

Consumer Information and Firm Pricing: Negative Externalities from Improved Information

We analyze the effect of consumer information on firm pricing in a model where consumers search for prices and matches with products. We consider two types of consumers. Uninformed consumers do not know in advance their match values with firms, whereas informed consumers do. Prices are lower the greater the proportion of uninformed consumers. Hence uninformed consumers exert a positive externality on the others, in contrast to standard results. This leads to socially excessive investment in gathering prior information when aggregate demand is price-sensitive.     

VERTICAL DIFFERENTIATION AND THE DISTRIBUTION OF INCOME

The paper analyses the effects of income concentration on the behaviour of a duopoly with vertical product differentiation and uncovered market. By using a trapezoid distribution, we solve explicitly for market equilibrium as a function of a mean preserving spread of the income distribution. We show that overall more concentrated incomes imply stronger product differentiation, as the presence of a large share of middle‐income consumers stimulates a price competition, whose effects are dampened through an enlargement of the quality spread. While the high‐quality advantage and market coverage increase unambiguously in the degree of income concentration, the behaviour of prices is non‐monotone in the distribution parameter.     

Screening in a Matching Market

Contract design under incomplete information is often analysed in a bilaterally monopolistic setting. If the informed party's reservation value does not depend on its private information (its type), it is a standard result that the uninformed side offers "low" types distorted contracts to reduce the information rent left to "high7rdquo; types.
We challenge this result by embedding contract design in a matching market environment. We consider a market where players meet pairwise and where, in each match, either side may be chosen to make a take-it-or-leave-it offer. As frictions become sufficiently low, we find that the set of equilibria is independent of whether there is complete or incomplete information. In particular, all contracts are free of distortions.     

Competition and confidentiality: Signaling quality in a duopoly when there is universal private information

We model non-cooperative signaling by two firms that compete over a continuum of consumers, assuming each consumer has private information about the intensity of her preferences for the firms' respective products and each firm has private information about its own product's quality. We characterize a symmetric separating equilibrium in which each firm's price reveals its respective product quality. We show that the equilibrium prices, the difference between those prices, the associated outputs, and profits are all increasing functions of the ex ante probability of high safety. If horizontal product differentiation is sufficiently great then equilibrium prices and profits are higher under incomplete information about quality than if quality were commonly known. Thus, while signaling imposes a distortionary loss on a monopolist using price to signal quality, duopolists may benefit from the distortion as it can reduce competition. Finally, average quality is lower since signaling quality redistributes demand towards low-quality firms.     

Informed trade,uninformed trade and stock price delay

The probability of informed trading (PIN), a measure of information-based trading risk, has been broadly applied to empirical studies on asset pricing. However, it is still controversial whether PIN measures exclusively the risk of firm-specific private information or it also captures the private interpretation of market wide public information. This article examines the relevance of PIN to the delayed response of stock prices to market-wide information. We find that PIN significantly explains individual stock price delay even controlling for size, liquidity and risk, and low-PIN stock prices adjust to market information more rapidly not only because of a notably high level of informed trading but also an even much higher level of uninformed trading. Our findings support the notion that PIN also captures the private skilled interpretation of public common factor information by sophisticated investors, and provide new empirical evidence on how information-based trading affects the speed at which stock prices adjust to information.     

Experimentation in Markets

We present a model of entry and exit with Bayesian learning and price competition. A new product of initially unknown quality is introduced in the market, and purchases of the product yield information on its true quality. We assume that the performance of the new product is publicly observable. As agents learn from the experiments of others, informational externalities arise.
We determine the Markov Perfect Equilibrium prices and allocations. In a single market, the combination of the informational externalities among the buyers and the strategic pricing by the sellers results in excessive experimentation. If the new product is launched in many distinct markets, the path of sales converges to the efficient path in the limit as the number of markets grows.     

Credence Goods,Misleading Labels,and Quality Differentiation

Due to differences in information disclosure mechanisms, consumer misinformation about the quality of many credence goods is more endemic at intermediate levels of the quality spectrum rather than at the extremes. Using an oligopoly model of vertical product differentiation, we examine how consumers’ overestimation of the quality of intermediate-quality products affects firms’ incentives to improve product quality. The firms non-cooperatively choose the quality of their product before choosing its price or quantity. Irrespective of the nature of second stage competition, Bertrand or Cournot, we find that quality overestimation by consumers increases profit of the intermediate-quality firm, and motivates it to raise its product’s quality. In response, the high-quality firm improves its product quality even further but ends up with lower profit. Overall, average quality of the vertically differentiated product improves, which raises consumer surplus. Social welfare increases when the firms compete in prices but falls when they compete in quantities.     

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.     

Rational panics and stock market crashes

This paper offers an explanation for stock market crashes which focuses on the role of rational but uninformed traders. We show that uninformed traders can precipitate a price crash because as prices decline, they surmise that informed traders received negative information, which leads them to reduce their demand for assets and drive the price of stocks even lower. The model yields several implications, such as that crashes can occur even when the fundamentals are strong, and that the magnitude of the crash depends on the fraction of uninformed investors and the amount of unsophisticated passive investing present in the market.     

Revisiting the Lemons Market

This article extends the standard competitive adverse selection model by allowing for qualitatively different information structures of agents on the informed side of the market. Using the stylized framework of the market for used cars, we examine the welfare properties of equilibria under the assumption that a fraction of the sellers remains uninformed about a parameter that is relevant for their own transaction. Whether market performance increases or decreases in the number of uninformed sellers is shown to depend on (1) the potential gains from trade in the market and (2) the average quality of the sellers' information structure.     

Ignorance Is Bliss as Trade Policy

Consider domestic consumers that purchase from foreign firms. A presumption would be that consumers prefer being informed when quality is uncertain and exogenous. However, in a multifirm framework based on previous models, consumers can be worse off if they are informed of the quality. Further, in the Salop-circle model, consumers may prefer not learning even though expected high-quality output is greater with learning. Moreover, the possibility that consumers prefer uncertainty increases with the probability that products are of low quality. Essentially, the benefit of screening quality (better matching) can be less than its cost (higher prices from market segmentation).     

From ultimatum to Nash bargaining: Theory and experimental evidence

We consider a sequential two-party bargaining game with uncertain information transmission. When the first mover states her demand she does only know the probability with which the second mover will be informed about it. The informed second mover can either accept or reject the offer and payoffs are determined as in the ultimatum game. Otherwise the uninformed second mover states his own demand and payoffs are determined as in the Nash demand game. In the experiment we vary the commonly known probability of information transmission. Our main finding is that first movers’ and uninformed second movers’ demands adjust to this probability as qualitatively predicted, that is, first movers’ (uninformed second movers’) demands are lower (higher) the lower the probability of information transmission. JEL Classification C72 · C78 · C92