为何招标采购偏好'低于均价中标法'

摘要

Recently there are many arguments about whether the below average bid auction should be applied in the area of procurement bid auctions.This paper first proves there does not exist a symmetric Bayesian Nash equilibrium in strictly increasing bid strategies in the standard below average bid auction.Then we conduct an empirical research based on a procurement bid dataset of a large grid firm in China to analyze the bidding behavior in it.It is found that in the empirical study,bidders will bid contingent on their real costs and in the long time,this mechanism can encourage bidders to cut down their profits, which can lead to a low procurement cost.Moreover, below average bid auction can make bidders have an expectation of profit at a stable low level,which can guide bidders to bid a low but rational price to avoid winner's curse in a focal bid auction.These results support the wide use of below average bid auction in procurement in reality.Finally, we also find the evidence that below average bid auction can create incentives to coordinate bids to manipulate the trimmed average bid price.Our work provides managerial implications for the proper application of below average bid auction.%低于均价中标法招标机制被广泛应用于各类招标采购中,但其合理性存在大量争议.文章首先在理论上证明了标准低于均价中标法下投标人不存在随真实成本严格递增的贝叶斯纳什均衡报价策略,然后基于某大型电力公司的招标采购数据,对投标行为进行实证分析,发现低于均价中标法下投标人报价可以反映其真实成本,且该机制在时间趋势上既可以激励投标人压缩利润,降低采购成本,又可以引导投标人形成稳定的低利润预期,指导投标人报"合理低价",防止"赢者诅咒"现象的发生.以上发现均说明低于均价中标法在业界被广泛应用的合理性,但这种招标机制也易于催生投标人间串谋.文章研究为低于均价中标法的合理使用提出了管理建议.