Bertrand Competition for Inputs and Walrasian Outcomes
建立了一个商人先向供应商采购再转售给消费者的两阶段定价博弈模型，发现当需求弹性时唯一子博弈完美均衡是瓦尔拉斯均衡，而需求无弹性时则非瓦尔拉斯；若商人先向消费者出售远期合约再竞争供应，则均衡总是瓦尔拉斯均衡。
Market making by merchants, who obtain stock from suppliers and resell it to con sumers, is modeled as a two-stage pricing game with winner-take-all c ompetition for the inputs (in contrast to fixed-capacity models). The re is a unique, subgame-perfect Nash equilibrium (SPNE) which is Walr asian for elastic demand and non-Walrasian for inelastic demand. Alte rnatively, when merchants first sell forward contracts to consumers a nd then compete for supplies, the unique SPNE is always Walrasian. Th us, the author has an equilibrium model in which Walrasian price aris es not from the benevolent actions of a fictitious auctioneer, but fr om optimal price-setting behavior of merchants. Copyright 1988 by American Economic Association.