Manipulation Through Biased Product Reviews*

We study a signal-jamming model of product review manipulation in which rational consumers consult product reviews and price to better estimate a product's quality, and a firm, whose quality is either high or low, chooses its price and how much bias to insert into product reviews. We show that both firm types always exert positive effort to manipulate product reviews, and, depending on the equilibrium price level, one or both of them can increase its sales. When the high-type firm exerts more effort than the low-type, review manipulation benefits consumers by raising [lowering] their demand for the high-quality [low-quality] product.     

The Strategic Effect of Bundling: A New Perspective

This paper investigates the strategic effect of the bundling strategy that is adopted by a multi-product firm that produces two complementary goods and faces one single-product rival in each market. I consider both the Cournot and Bertrand cases. When firms compete in quantities, bundling is completely ineffective. Under price competition, selling as a package is profitable when market competition is particularly tough. In such circumstances, the multi-product firm resorts to bundling to dampen the negative impact of low brand differentiation and/or scarce product complementarity. However, overall prices increase as a result of bundling, and not only consumer surplus, but also total social welfare, shrink.     

Social comparison among competing firms

Extending social comparison theory to the context of interfirm competition, we investigate whether and under what conditions firms may benefit by deviating from consumers' views concerning firm comparisons. Based on all of the possible dyadic competitive comparisons among the 26 automakers in the United States, we found that: (1) a focal firm enjoys a greater increase in sales than the target firm when it compares itself with a more reputable target firm, even though consumers do not perceive the focal firm to be comparable to the more reputable firm; and (2) a focal firm enjoys a greater increase in sales than the target firm when it avoids comparison with a less reputable target firm, even though consumers compare the focal firm with the less reputable firm. Copyright © 2011 John Wiley & Sons, Ltd.     

Pricing with Endogenous Direct Advertising in a Monopoly

This paper develops a model of informative advertising in which a firm builds a database using its historical sales records in order to directly target ads on those consumers who have a high probability of purchasing its products. We show that the firm can use this type of direct advertising as a screening mechanism to identify high demand consumers. As a result, direct advertising can work essentially as a device to increase a firm's monopoly power. From a social point of view, this implies that the transition from traditional mass-advertising to direct advertising can generate a trade-off between higher advertising efficiency and greater monopoly power. We compute the model to shed light on the relative strength of these two forces, and find that while direct advertising might have a substantial negative impact on consumers, this advertising technology can only occasionally reduce welfare.     

Strategic segmentation of a market

When competing firms target information towards specific consumers through direct marketing activities, complete segmentation of markets can result. We analyze a two-stage duopoly where, prior to price competition, each firm targets information to specific consumers and only consumers informed by a firm can buy from it. This has the effect of endogenously determining market segments in a model of ‘sales'. In equilibrium, pure local monopoly emerges; firms target and sell to mutually exclusive market segments. When the cost of marketing approaches zero, market shares reflect relative production efficiency (equal shares when firms are symmetric); this may not be the case when marketing cost is high.     

All-pay competition with captive consumers

We study a game in which two firms compete in quality to serve a market consisting of consumers with different initial consideration sets. If both firms invest below a certain threshold, they only compete for those consumers already aware of their existence. Above this threshold, a firm is visible to all and the highest investment attracts all consumers. On the one hand, the existence of initially captive consumers introduces an anti-competitive element: holding fixed the behavior of its rival, a firm with a larger captive segment enjoys a higher payoff from not investing at all. On the other hand, the fact that a firm’s initially captive consumers can still be attracted by very high quality introduces a pro-competitive element: a high investment becomes more profitable for the underdog when the captive segment of the dominant firm increases. The share of initially captive consumers therefore has a non-monotonic effect on the investment levels of both firms and on consumer surplus. We relate our findings to competition cases in digital markets.     

Waterfall Versus Sprinkler Product Launch Strategy: Influencing the Herd

A seller decides the price and sequence in which a product of unknown value is introduced to consumers. Consumers inspect the product before consumption and observe past prices and sales. Consumption at a high price is informative for later consumers as it indicates that the product is likely to be of high value. I show that on an average prices decrease over time. However, expected revenue on an average rises over time. For a high enough discount factor, I find that for extreme beliefs the firm introduces the product to all consumers but for intermediate values the product is introduced only to one consumer.     

Incentives through consumer learning about tastes

We consider a long-lived firm that faces an infinite sequence of finitely-lived consumers. In each period, the firm can exert either high or low effort, which is the firm's private information. When consumers learn about the firm's talent from the outcomes of previous transactions, there exists no equilibrium in which the firm always exerts high effort. However, when consumers learn about their own tastes, such an equilibrium can exist. Consumer learning about tastes therefore is an alternative to reputational concerns that produces stable incentives. We discuss the implications of this mechanism for advertising, advertising content, and consumer education.     

Behavior based price personalization under vertical product differentiation

We study price personalization in a two period duopoly with vertically differentiated products. In the second period, a firm not only knows the purchase history of all customers, as in standard Behavior Based Price Discrimination models, but it also collects detailed information on its old customers, using it to engage in price personalization. The analysis reveals that there exists a natural market for each firm, defined as the set of customers that cannot be poached by the rival in the second period. The equilibrium is unique, except when firms are ex-ante almost identical. In equilibrium, only the firm with the largest natural market poaches customers from the rival. This firm has highest profits but not necessarily the largest market share. Aggregate profits are lower than under uniform pricing. All consumers gain, total welfare is higher herein than under uniform pricing if firms’ natural markets are sufficiently asymmetric. The low quality firm chooses the minimal quality level and a quality differential arises, though the exact choice for the high quality depends upon the cost specification.     

An antitrust analysis of bundled loyalty discounts

Consider a monopolist in one market that faces competition in a second market. Bundled loyalty discounts, in which customers receive a price break on the monopoly good in exchange for making all purchases from the monopolist, have ambiguous welfare effects. Such discounts should not always be treated as a form of predatory pricing. In some settings, they act as tie-in sales. Existing tests for whether such discounts violate competition laws do not track changes in consumer surplus or total surplus. We apply a new test to an illustrative example based on SmithKline that assumes the “tied” market has homogeneous goods. If the tied market is characterized by Hotelling competition, bundling by the monopolist causes the rival firm to reduce its price. In numerical examples, we find that this can deter entry or induce exit.     

Modeling Competition over Multiple Variables under Limited Consumer Awareness*

When analyzing firm competition over two strategic variables (e.g., quality and price), it is important to decide whether to model it as a one-stage or a two-stage game. Our analysis focuses on markets in which consumers are not aware of all alternatives. We find that, if consumers are sufficiently unaware, both the one-stage and the two-stage equilibria of the game that explicitly models limited awareness are close to the one-stage equilibrium of the standard game, which assumes full awareness. Therefore, markets in which consumers have limited awareness can be studied with standard models, provided that the one-stage game is analyzed.     

Underpromise and overdeliver? - Online product reviews and firm pricing

We consider a signaling model capturing the introductory and the mature phase of a product. Information concerning product quality is transmitted between consumers through reviews, which partially depend on the expectations consumers had prior to their purchase. When future sales are sufficiently important, a novel tension arises: High-quality types may want to underpromise and overdeliver by imitating low types in order to get a better review. We show the existence of a Pareto-improving separating equilibrium. Both more informative reviews and price transparency can lead to higher prices. Our analysis reveals a new rationale for loss-leadership.     

分散决策下的双渠道供应链补偿策略——基于消费者渠道选择行为

为了有效解决由于对消费者的争夺从而引发的渠道之间关于定价、服务水平、利润等方面的冲突,基于消费者渠道选择行为,构建了网络直销市场与传统零售市场需求模型和双渠道供应链利润模型,运用Stackelberg模型,在制造商与零售商实施分决策时,通过制造商对零售商实施补偿激励前后的对比,分析了消费者渠道选择行为对网络直销渠道和传统零售渠道定价、制造商与零售商利润以及供应链总利润的影响,并求得最优定价及制造商的最优补偿额度和零售商的最优销售努力水平,进行了不同情况下的双渠道供应链利润的比较分析。结果表明,无论制造商是否实施补偿激励,都应随着网络消费者比例的增加而增加其网络直销价格;零售商的零售渠道价格应根据网络消费者比例的增加先降低到一定水平后再提升。当更多的消费者选择网络直销渠道时,制造商的补偿激励水平和零售商的销售努力程度均会下降。制造商应提高其补偿水平,进而激发零售商提高销售的努力水平,并使双方利润及供应链总利润最大化。研究结果为基于消费者选择行为的供应链补偿研究提供了新方法,对双渠道的供应链补偿研究有借鉴意义。     

Optimal bundle pricing under correlated valuations

We study optimal pricing issues for a monopolist selling two indivisible goods to a continuum of consumers with correlated private valuations over the goods, where the (positive or negative) correlation is modeled using copulas in the Fréchet family. We derive explicit optimal pricing schemes and comparative statics results for various environments in our setting. The optimal pricing schemes can take several forms, including pure bundling, partial mixed bundling, and mixed bundling, depending jointly on the degrees of asymmetry and correlation of the consumers’ valuations. The explicit optimal pricing schemes also enable us to investigate whether and how the monopolist’s profit can be further improved via random assignments.     

Collusion Under Imperfect Monitoring with Asymmetric Firms

We explore the effects of asymmetries in capacity constraints on collusion where market demand is uncertain and where firms’ sales and prices are private information. We show that all firms can infer when at least one firm's sales are below some firm‐specific ‘trigger level.’ When firms use this public information to monitor the collusive agreement, price wars may occur on the equilibrium path. Symmetry facilitates collusion but, if price wars are sufficiently long, then the optimal collusive prices of symmetric capacity distributions are lower on average than the competitive prices of asymmetric capacity distributions. We draw conclusions for merger policy.     

Vertical product differentiation,network externalities,and compatibility decisions

We analyse the subgame perfect equilibrium of a four-stage game in a model of vertical product differentiation, where the consumer’s evaluation of a product depends on its inherent quality and on its network’s size. First, two firms choose their product’s inherent quality. Then they may mutually agree on providing an adapter before competing in prices. Finally, consumers buy. We find that, despite the high quality firm’s preference for incompatibility, an adapter is always provided in equilibrium. Social welfare is greater than without an adapter and can be improved by regulating compatibility only in those cases where qualities are differentiated too much.     

Compatibility and Bundling with Generalist and Specialist Firms

I analyze compatibility and bundling choices when one generalist firm offering both components of a system competes against two specialist firms each supplying one component only (but not the same one). I show that the generalist firm may have an incentive to choose incompatibility or engage in pure bundling when one component is less differentiated than the other. In this case, the system is more differentiated than the relatively undifferentiated component, and so under incompatibility the specialist firm that produces the undifferentiated component will relax price competition. This may result in higher profits for some of the competing firms.     

Speed-to-Market and New Product Performance Trade-offs

When pressed to accelerate a development effort, more than a few managers have responded in terms such as “Good, fast, cheap … Pick any two.” Time-to-market decisions clearly play an important role in determining the ultimate success or failure of a new product. Just as clearly, however, speed to market is not the sole determinant of success. The seemingly offhanded “Pick any two” response points to the tradeoffs that product development managers must make in their decisions about development time and costs. Barry Bayus discusses the relationship between product development time and costs, and he fomulates a mathematical model that simultaneously considers the decisions regarding time-to-market and product performance levels. He applies the model to two competitive scenarios, and he identifies the optimal entry timing and product performance decisions for various market, demand, and cost conditions. In the first scenario, a firm must decide whether to accelerate development efforts to catch a competitor that has just introduced a new product. Analysis of the tradeoffs among the various parameters in the model suggests that fast development of low-performance products is optimal under the following conditions: a relatively short window of market opportunity, a weak competitor, and relatively high development costs. For example, if the competitor is weak, high performance levels are not necessary and the firm can safely reduce time-to-market. Under the same scenario (that is, accelerating development to catch a competitor), the analysis suggests that fast development of products with high performance levels is optimal under conditions of relatively high sales and relatively flat development costs. In the second scenario, the firm must decide whether to speed development efforts to beat the competition to market. Analysis of the various tradeoffs for this scenario suggests that first-to-market status for a product with a high performnace level is optimal under the following conditions: a relatively long window of market opportunity, relatively high sales, and relatively flat development costs. With a long product lifecycle, stable margins, and high sales, the firm can generate sufficient revenue to offset the increased cost incurred in speeding a high-performance product to market. Beating a competitor to market with a low-performance product is never optimal for the cases considered here.     

Mergers of complements and entry in innovative industries

I study a merger between producers of complement inputs facing potential entry, with investment by the incumbents in deterministic cost reduction and by the entrants in probabilistic innovation, and then competition in prices. The merger solves Cournot complementarity problems in investment and pricing, which is what makes it profitable but also potentially anti-competitive. When the demand is inelastic the merger harms consumers by reducing R&D of the entrants if the incumbents are efficient enough (always when bundling is adopted). Instead, with a demand elastic enough, the merger increases consumer surplus (even with bundling).     

Tying in evolving industries,when future entry cannot be deterred

We show that the incentive to engage in exclusionary tying (of two complementary products) may arise even when tying cannot be used as a defensive strategy to protect the incumbent’s dominant position in the primary market. By engaging in tying, an incumbent firm sacrifices current profits but can exclude a more efficient rival from a complementary market by depriving it of the critical scale it needs to be successful. In turn, exclusion in the complementary market allows the incumbent to be in a favorable position when a more efficient rival will enter the primary market, and to appropriate some of the rival’s efficiency rents. The paper also shows that tying is a more profitable exclusionary strategy than pure bundling, and that exclusion is the less likely the higher the proportion of consumers who multi-home.