Multiproduct-Firm Oligopoly: An Aggregative Games Approach

• 成果类型: Article
• 署名作者: Nocke, Volker; Schutz, Nicolas
• 署名单位: University of California System; University of California Los Angeles; Center for Economic & Policy Research (CEPR); University of Mannheim
• 刊物名称: ECONOMETRICA
• ISSN/ISSBN: 0012-9682
• DOI: 10.3982/ECTA14720
• 发表日期: 2018
• 页码: 523-557
• 关键词: european car market; strategic complementarities; product differentiation; INTERNATIONAL-TRADE; comparative statics; horizontal mergers; Cournot oligopoly; potential games; choice model; equilibrium

摘要

We develop an aggregative games approach to study oligopolistic price competition with multiproduct firms. We introduce a new class of IIA demand systems, derived from discrete/continuous choice, and nesting CES and logit demands. The associated pricing game with multiproduct firms is aggregative and a firm's optimal price vector can be summarized by a uni-dimensional sufficient statistic, the -markup. We prove existence of equilibrium using a nested fixed-point argument, and provide conditions for equilibrium uniqueness. In equilibrium, firms may choose not to offer some products. We analyze the pricing distortions and provide monotone comparative statics. Under (nested) CES and logit demands, another aggregation property obtains: All relevant information for determining a firm's performance and competitive impact is contained in that firm's uni-dimensional type. We extend the model to nonlinear pricing, quantity competition, general equilibrium, and demand systems with a nest structure. Finally, we discuss applications to merger analysis and international trade.