Abstract: We further study critical discount and reserve price’s effects on the stability of two cartel collusion mechanisms(strong cartel and weak cartel)in repeated procurement auctions . We draw two conclusions: (1)when collusive member's discount is larger than critical discount, no members will betray the collusion agreement, or else collusion will collapse; (2)compared with simple reserve price and Nash reserve price, the minimal deterrent reserve price is the most effective reserve price to deter collusion and earn certain profit. The research results help to enhance the understanding of two kinds of operation mechanism of the cartel collusion mechanism in repeated purchase auction, and enrich the theory research of supervision mechanism and strategies of collusion in repeated purchasing environment.

Key words: repeated procurement auction, strong/weak cartel, price collusion, the stability of collusion, the smallest reserve price

摘要： 深入研究临界贴现因子和保留价格两种因素对重复采购竞拍中的两种卡特尔串谋机制稳定性的影响。研究表明:(1)当串谋成员的贴现因子超过临界贴现因子时,没有成员会背叛串谋协定;(2)相比简单保留价格和纳什均衡保留价格,本文提出的阻挠串谋的最小保留价格最能有效阻止销售方串谋行为并确保采购方一定收益。研究结果有助于增进对重复采购拍卖下两种卡特尔串谋机制的运作机理的理解,丰富了重复采购环境下竞拍串谋监管机制和策略的理论研究内容。

关键词: 重复采购竞拍, 卡特尔, 价格串谋, 串谋稳定性, 最小保留价格