Sufficient Decisions in Multi‐Sided and Multiproduct Markets

We show that in many models where firms make multiple decisions, analysis can be made more tractable by re‐formulating the model into one in which each firm makes a single choice, which we call a sufficient decision. The transformation allows application of standard techniques in these settings, including pass‐through for tax incidence and upward pricing pressure for merger analysis. The transformation works because the assumption of profit maximization links the firms’ decisions together. Examples include models of monopoly and oligopoly in two‐sided markets, where a natural sufficient decision may be the number of transactions that the firm facilitates, and multiproduct markets.     

Fat Products

The economics literature generally considers products as points in some characteristics space. With more products being flexible or self-customizable to some degree, it makes sense to model products with positive measure. I develop a model of firms which can offer interval-long "fat" products in the spatial model of differentiation. Contrary to the standard results, profits of the firms can decrease with increased differentiation in the market—there is a standard effect of lowering the incentive to cut prices, but there is also an incentive to provide more content, resulting in higher costs and possibly overall losses.     

Competing for Consumers with Self‐Control Problems

I examine strategic implications of competing for consumers with self‐control problems. For investment goods, like health clubs, I find that the equilibrium sign‐up (lump‐sum) fees decrease when competition intensifies, similarly to prices in standard oligopoly models. However, the equilibrium attendance (per‐unit) price increases due to firms' deteriorated ability to take advantage of consumers' self‐control problems. Moreover, firms earn less profit due to consumers' self‐control problems—the firms have a unilateral incentive to charge per‐unit fees lower than the marginal cost; however, they cannot make up the lost margins by increasing the lump‐sum fee, due to competition. I also show that for plausible parameter regions the market adjusts to consumers' self‐control problem in such a way that firms play the standard equilibrium strategies that they would have engaged in with fully rational consumers, with identical market outcomes. Most of the results are qualitatively the same for leisure goods (for example, credit cards); however, some results are reversed: the per‐unit fees are higher than marginal cost and decrease as competition intensifies.     

The effects of social- and self-motives on the intentions to share positive and negative word of mouth

We examine social- and self-motives as drivers of Word of Mouth (WOM). The main proposition is that the transmitter expects to gain personal and social benefits from sharing his opinion about a brand. The gains are in the form of expected satisfaction of self- and social-needs. In the research model, self-needs (i.e., self-enhancement and self-affirmation) are considered the initial driver of WOM. The desire for their satisfaction through WOM results in an intended social interaction, which in turn triggers social-motives: social-needs (i.e., social comparison and social bonding) and social-intentions (i.e., helping others and providing social information). WOM is the outcome of the intention to engage in a social interaction that is initiated by the intention to satisfy self-needs. Through an empirical analysis, we examine how the underlying mechanism varies for positive and negative WOM. Positive WOM is motivated primarily by the need for self-enhancement, and negative WOM is motivated by the need for self-affirmation. The need for social comparison affects both valences of WOM, the need for social bonding affects only positive WOM, and intention to help others and share social information affect only negative WOM. The findings suggest that discussing brands can be a mechanism for acquiring personal and social benefits, and consequently, promotional campaigns should highlight the gains customers accrue through WOM.     

Effects of Joint Outsourcing on Consumer Welfare

This work models outsourcing under oligopolistic competition with nonlinear costs. I show that in a covered market, if each firm’s marginal cost before outsourcing is lower than the industry’s average cost, outsourcing leads to increased prices and decreased consumer welfare. Joint outsourcing is more profitable if the firms’ equilibrium quantity produced is in the economies of scale part of their cost curve.     

Anti‐Competitive Interconnection: the effects of the elasticity of consumers' expectations and the shape of the network effects function

I find that interconnection might cause the market to be less competitive, and might lead to an increase in the price firms charge for their product. Absent interconnection, firms compete for a consumer for two reasons. The first reason is to obtain revenue from selling the product to a consumer (as in the case without network effects). The second reason is that by expanding the network by one more consumer, the product becomes more attractive to all other consumers. Interconnection eliminates the second reason—when firms interconnect, they are no longer concerned with consumers' following the crowd. I show that consumers and society might be worse off from interconnection. I focus on two factors that make the (post‐interconnection) price increase larger: consumer expectations that are highly sensitive to prices and consumers putting a high value on small increases in network size at the equilibrium market shares. Both of these factors make firms highly competitive, but only if the firms' products' networks are not interconnected.