Referrals in search markets

This paper compares the equilibrium outcomes in search markets with and without referrals. Although it seems clear that consumers would benefit from referrals, it is not at all clear whether firms would unilaterally provide information about competing offers since such information could encourage consumers to purchase the product elsewhere. In a model of a horizontally differentiated product market with sequential consumer search, we show that valuable referrals can arise in the equilibrium: a firm will give referrals to consumers whose ideal product is sufficiently far away from the firm's offering. We allow firms to price-discriminate among consumers, and consumers to misrepresent their tastes. We found that the equilibrium profits tend to be higher in markets with referrals than in markets without. Consumers tend to be better off in the presence of referrals when search costs are not too low, and under a certain parameter range, referrals lead to a Pareto improvement.     

INNOVATION AND COMPETITIVE PRESSURE*

I analyze the effects of competition on process innovation and product introduction and obtain robust results that hold for a range of market structures and competition modes. It is found that increasing the number of firms tends to decrease cost reduction expenditure per firm, whereas increasing the degree of product substitutability, with or without free entry, increases it—provided that the average demand for product varieties does not shrink. Increasing market size increases cost reduction expenditure per firm and has ambiguous effects on the number of varieties offered, while decreasing the cost of entry increases the number of entrants and varieties but reduces cost reduction expenditure per variety. The results are extended to other measures of competitive pressure and to investment in product quality. The framework and results shed light on empirical strategies to assess the impact of competition on innovation.     

Experimenting to Learn about Demand in Duopoly with Forward‐Looking Consumers

Using a two‐period model, I show that competition between two symmetric duopolists trying to learn about unknown features of demand results in an informationally suboptimal process. Because a firm’s marginal return to price experimentation equals zero if the rival’s price is matched in the first period, myopic symmetric pricing arises in equilibrium even though a firm’s expected second‐period profit attains a local minimum. Furthermore, forward‐looking consumers suffer from ratcheting because their first‐period purchase decisions partly reveal their preferences, which exacerbates the informational suboptimality of the firms’ experimentation process without affecting their pricing. The role of firm asymmetries is also analyzed.     

MARKET PERFORMANCE WITH MULTIPRODUCT FIRMS*

We revisit the fundamental issue of market provision of variety associated with Chamberlin, Spence, and Dixit‐Stiglitz when firms sell multiple products. Both products and firms are (horizontally) differentiated. We propose a general nested demand framework where consumers first decide upon a firm then which variant to buy and how much (the nested CES is a special case). We use it to determine the market's biases when firms compete in product ranges and prices. The market system attracts too many firms with too few products per firm: firms restrain product ranges to relax price competition, but this exacerbates over‐entry.     

Competitive targeted online advertising

This paper examines how an online publisher utilizes its information about consumer preference to target advertising. In our model, two firms first bid for a prominent ad position in a publisher-organized position auction, and then compete on price in the subsequent product marketplace. We consider two dimensions of consumer heterogeneity. First, consumers are heterogeneous in product preference. Based on their tastes, some consumers prefer one product over the other, whereas other consumers may rank the products in an opposite order. Second, consumers differ in search preference, i.e., “nonshoppers” only consider the advertised product, while “shoppers” always search both firms’ products before buying. We show that targeted advertising based on product preference will mitigate price competition in product markets as well as competition in position auctions, the latter to the detriment of the publisher. In contrast, targeted advertising based on search preference always benefits the publisher, as the winning firm can charge monopoly prices to nonshoppers. We show that the publisher’s optimal choice is to utilize only the information about consumer search preference. We also explore the welfare implications of targeted advertising based on different types of consumer preference.     

On two-part tariff competition in a homogeneous product duopoly

We explore aspects of two-part tariff competition between duopolists providing a homogeneous service when consumers differ with respect to their usage levels. Competition in only one price component (the fee or the rate) may allow both firms to enjoy positive profits if the other price component has been set at levels different enough between firms. Fixing one price component alters the nature of competition, indirectly introducing an element of product differentiation. Endogenous market segmentation emerges, with the heavier users choosing the lower rate firm and the lighter users choosing the lower fee firm. When no price component can be negative, competition becomes softer, profits tend to be higher but there is also a disadvantage for the firm that starts with a higher fee than that of its rival.     

Selling cross-border in online markets: The impact of the ban on geoblocking strategies

We develop a model of strategic geoblocking, where two competing multi-channel retailers, located in different countries, can decide to block access to their online store from foreign consumers. We characterize the equilibrium when firms decide unilaterally whether to introduce geoblocking restrictions. We show that geoblocking allows firms to soften competition, but at the cost of lower demand. A ban on geoblocking leads to lower prices, both offline and online. However, when firms can invest in increasing online demand, the ban may have adverse effects on investment and social welfare. We extend our analysis to account for price discrimination and investigate the role of shipping costs.     

A more general model of price complexity

This paper analyses a model of competition where the firms set not only prices but also the complexity levels of their prices (which determine how difficult it is for consumers to assess the price offers). Unlike previous work, in this model, the firms’ confusion technology may be non-linear in the aggregate complexity level. The equilibrium probability of using high complexity increases in the number of firms but decreases in the convexity of the confusion technology. In large markets, the firms use high complexity almost surely. However, the industry profit converges to the highest level with concave technologies and to the lowest level with convex technologies. An increase in consumer sophistication, which benefits the consumers, may not reduce market complexity.     

Price competition when three are few and four are many

I examine price competition in a market for a homogeneous good when consumers observe prices subject to a random shock (perception error). When firms have symmetric costs, there exists a unique equilibrium in pure strategies, which is symmetric. When there are up to three sellers in the market, the sellers extract the entire consumer surplus. However, with at least four firms, assuming that the marginal cost is sufficiently low relative to consumers’ valuation, both consumers and producers may enjoy a positive surplus. The marginal-cost pricing is never observed in an equilibrium with finitely many firms. Potential policy implications are discussed.     

Monopolistic competition and a firm's product range

A model is presented which assumes that firms maximise profits with respect to both the number of varieties supplied as well as the output level of a typical variety. The incentive to produce more than one variety comes from a cost advantage due to inter-product economies. It is found that in a long-run free-entry equilibrium the industry is characterised by too few product varieties and each variety is over supplied compared to the welfare maximum for any conjectural variation elasticity. The former result also holds if the number of firms is held fixed.     

Vertical integration and product differentiation

We study a new channel of downstream rent extraction through vertical integration: competition for integration. Innovative downstream firms create value and profit opportunities through product differentiation, which however affects an upstream monopolist’s incentive to vertically integrate. By playing the downstream firms against each other for integration, the upstream firm can extract even more than the additional profits generated by the downstream firms’ differentiation activities. To preempt rent extraction, the downstream firms may then reduce differentiation, which reduces social welfare. We show that this social cost of vertical integration is more likely to arise in innovative and competitive industries, and that the competition for integration channel of downstream rent extraction is robust to upstream competition.     

Non-linear pricing and conscious consumption

We consider a duopolistic market in which a green firm competes with a brown rival and each firm sells two quality-differentiated products. We study optimal non-linear contracts offered by the two firms when consumers: (i) Are privately informed about their willingness to pay for quality, and (ii) differ in their environmental consciousness. We characterize how consumers with different valuations for quality self-select into firms and show that the ranking of qualities, relative prices and profits all depend on the interplay between consumers’ valuations and firms’ cost heterogeneity. Interestingly, when consumers’ valuations for quality are relatively low, the brown firm does not offer a low-quality variety. This contrasts with the situation of full information, in which both firms commercialize a high- and a low-quality variety. Hence, the lack of information about consumers’ valuations may not only favor the green firm in terms of higher prices and profits, but also reduce the product range offered by the brown rival.     

Oligopoly under incomplete information: On the welfare effects of price discrimination

We study competition by firms that simultaneously post (potentially nonlinear) tariffs to consumers who are privately informed about their tastes. Market power stems from informational frictions, in that consumers are heterogeneously informed about firms’ offers. In the absence of regulation, all firms offer quantity discounts. As a result, relative to Bertrand pricing, imperfect competition benefits disproportionately more consumers whose willingness to pay is high, rather than low. Regulation imposing linear pricing hurts the former but benefits the latter consumers. While consumer surplus increases, firms’ profits decrease, enough to drive down utilitarian welfare. By contrast, improvements in market transparency increase utilitarian welfare, and achieve similar gains on consumer surplus as imposing linear pricing, although with limited distributive impact. On normative grounds, our analysis suggests that banning price discrimination is warranted only if its distributive benefits have a weight on the societal objective.     

Computing welfare losses from data under imperfect competition with heterogeneous goods

We study the percentage of welfare losses (PWL) yielded by imperfect competition under product differentiation. When demand is linear, even if prices, outputs, costs and the number of firms can be observed, PWL is arbitrary in both Cournot and Bertrand equilibria. If in addition the elasticity of demand (resp. cross elasticity of demand) is known, we can calculate PWL in a Cournot (resp. Bertrand) equilibrium. When demand is isoelastic and there are many firms, PWL can be computed from prices, outputs, costs and the number of firms. We find that price–marginal cost margins and demand elasticities may influence PWL in a counterintuitive way. We also provide conditions under which PWL increases or decreases with concentration.     

Firm Heterogeneity,New Investment and Acquisitions

This paper presents a model of investment in which heterogeneous firms choose between new investment and acquisitions. New investment involves purchasing a new plant for an existing variety. Acquisitions involve purchasing a plant and a variety from a selling firm. Using a variable‐elasticity demand system, I show that if varieties within a differentiated industry are imperfect substitutes, mid‐productivity firms invest. As varieties approach perfect substitutability, high‐productivity firms invest. For both cases, within the region of investing firms, the most productive choose acquisitions over new investment. In analyzing firm‐level data from Compustat, I find evidence that supports these predictions.     

Product Location with Foresight

Traditional location literature concludes that firms will optimally differentiate in order to alleviate a tendency toward competitive pricing. However, it has recently been shown that firms will minimally differentiate if they (correctly) anticipate an absence of price competition. This paper examines the relationship between product location and the sustainability of cooperative pricing, in horizontally and vertically differentiated markets. Further, it describes equilibrium locations when firms are able to choose their locations jointly and when they must choose independently.     

Technology Choice and Market Structure: strategic aspects of flexible manufacturing

This paper shows that the adoption of flexible manufacturing techniques by firms leads to a tougher price regime. However, consumers may not benefit since the tougher regime deters entry. Flexible manufacturing's ability to deter entry is moderated by two factors: non-prohibitive costs of re-anchoring flexible manufacturing processes and the possibility that entrants choose to produce niche products using designated technologies rather than adopt flexible manufacturing. Market preemption that deters entry will be characterized by excessive product variety. Alternatively, flexible manufacturers may prefer to accommodate entry by small-scale, niche firms. Moreover, ownership matters in determining equilibrium product configurations.     

Dynamic Product Diversity

This paper examines the frequency of new product introductions in monopoly markets where demand is subject to temporary satiation. Consumers' taste for diversity is satisfied over time as new varieties are introduced to the market. If two varieties are introduced in consecutive periods then they become imperfect substitutes and the firm has an incentive to raise prices and sell each one to consumers with higher valuations (better preference matching). Higher frequency can also generate market expansion. However, under strong temporary satiation, better preference matching may dominate and the frequency of new product introductions may become socially excessive.     

Information Generation in Vertically Differentiated Markets*

In a model of vertical competition two firms draw costly public signals that are informative about the quality of their products and then competitively set prices. When each firm generates information independently from the other, there will be overinvestment (underinvestment) in information generation if the market share of the quality follower in the subsequent market equilibrium is high (low). Moreover, information generation by one firm has a positive externality on the other firm. Hence, coordination (e.g., via industry associations) increases information generation. When product qualities are endogenous, information generation may prevent quality degradation and thus have an additional social benefit.     

Market regulation of voluntary add-on contracts

This paper analyzes contract choices and the effectiveness of consumer protection policies when firms can offer voluntary add-on insurance for their products. We develop a model in which a base product can be sold together with a voluntary extended warranty contract that insures consumers against the risk of product breakdown. Some consumers do not pay attention to extended warranties before making base product choices, but overestimate the value of such warranties at the point of sale. Under retail competition, the consumers’ option to buy multiple base products can endogenously create a base price floor that may prevent firms from redistributing the full warranty profits via loss-leadership. Inducing competition in the warranty market weakly increases consumer welfare and weakly outperforms a minimum warranty standard, which can even reduce consumer surplus. The results are consistent with the effects of recent changes regarding extended warranty regulation by UK legislators.