Do Consumers Search for the Highest Price? Oligopoly Equilibrium and Monopoly Optimum in Differentiated-Products Markets
构建了一个消费者搜索替代品最优组合的模型，分析寡头企业进入、产品选择和定价的子博弈完美均衡，并与多产品垄断者的最优选择比较，发现均衡价格随市场内替代品数量增加而上升，且垄断能提高福利。
We develop a model of search among substitutes for the best combination of commodity variant and price, in which the structure of search costs is manipulable by the suppliers of these variants, e.g., by joining an existing market or opening a new one. We analyze the subgame-perfect equilibria arising in a multistage game involving specialized firms' choice of entry, variant, and price, and we compare them to a multiproduct monopolist's optimal choice. We show that equilibrium prices increase in the number of substitutes sold in one market and that, in the situation considered here, monopoly increases welfare.