逢低买入与固定价格机制比较研究

研究了一种新型的基于Internet 的动态价格机制———逢低买入(group-buying auction) . 利 用独立私有估价模型,分析了规模经济条件下商家采用逢低买入的盈利情况;对逢低买入与固 定价格机制进行了比较. 通过数值分析,给出了逢低买入优于固定价格机制的条件,指出逢低 买入的适用环境.     

生产能力无限时逢低买入与固定价格机制的比较

逢低买入是一种新型的基于网络的动态价格机制,它通过联合单个消费者形成规模来获得价格折扣。作为双向拍卖的一种变体,逢低买入的适用条件是亟待研究的问题。本文通过研究存在规模效应的前提下,当商家能够完全满足消费者的需求时,采用逢低买入拍卖所能获得的收益情况,证明了在这种情况下逢低买入将会绝对优于固定价格机制,从而表明逢低买入适用于这种环境。     

开放式逢低买入中买家数量确定的投标决策

逢低买入是一种新型的在线动态价格机制。本文以B2B开放式逢低买入拍卖为研究对象,在买家数量确定且独立投标的条件下,将已有的针对两个价格水平下买家最优订货决策拓展到更复杂的多个价格水平的最优订货决策问题。本文提出的零售商投标决策定理,不仅满足了买家的实际需求,也提高了决策的实用性。     

卖方边际成本可变的多物品多属性逆向拍卖研究

研究卖方边际成本可变的多物品多属性逆向拍卖问题。首先,根据卖方边际成本可变的特点设计了一种多轮逆向拍卖机制;其次,基于近视最佳反应策略的基本假设,分析卖方的投标策略;最后,利用仿真实验方法,研究买方事先公布估价信息对拍卖的影响。基本结果是:本拍卖机制在多数情况下是有效率的;相对买方不公布估价信息的拍卖机制,买方事先公布估价信息的多物品多属性拍卖具有稍差的市场效率,但能够显著地提高拍卖收敛速度。     

双边市场中平台企业搭售行为分析

搭售是现实中双边平台企业常用的促销策略之一。通过构建一个两阶段完全信息动态博弈模型,将买方分为搭售喜好型和搭售无差异型,从垄断和竞争两种情形研究了双边平台企业采取搭售策略时,具有不同搭售偏好的买方对最优均衡解的影响以及相应的社会福利变化。研究发现:不论是垄断情形还是竞争情形,搭售对买卖双方均衡进入价格的影响都不确定,而搭售产品的定价则按照传统单边市场的定价方式制定;垄断情形下,搭售能增加买方数量、卖方数量及双边平台企业的利润,而竞争情形下,搭售产品成本较小的双边平台企业将获得较大买方数量、卖方数量及利润。在两种情形下的买方总效用、卖方总效用以及社会总福利均随搭售喜好型买方数量的增加而增加。     

基于Priceline的买方/卖方定价收益管理问题

以著名逆向拍卖网站 Priceline 为背景,研究买方定价和卖方定价下的收益管理问题.假定顾客到达是一任意的更新过程,决策时刻为顾客到达时刻,所以决策是离散时间的.建立了两种定价方式下的马氏决策过程模型,获得了最优策略的表达式.在传统收益管理问题中,通常是卖方定价、连续时间决策、同时需要假定顾客到达是一 Poisson 过程.对于买方定价,文中证明了,卖方是否知道到达顾客的报价信息不影响他的收益;同时,随着剩余物品数的增加,卖方的期望收益递增,而边际收益递减,最优价格(或报价)递减.文中讨论两种定价方式下卖方的期望收益之间的关系.考虑了顾客需求是多重的情形.最后,数值分析表明文中所得的结论是成立的.     

固定价格与英式拍卖同时使用时顾客行为分析

很多网站采用在英式拍卖中加入固定价格选项的方式销售多件同类商品.我们证明了,在此规则下存在一个弱占优投标策略.若顾客对商品的估价低于固定价格,那么,当拍卖价格低于他的估价时,该顾客参与拍卖,且以自己的估价作为报价是他的弱占优投标策略;否则,当拍卖价格超过他的估价时,他退出拍卖.若顾客对商品的估价高于或等于固定价格,他会在参与拍卖和接受固定价格之间进行选择;若他参与拍卖,将固定价格作为报价是他的弱占优投标策略.我们发现,该顾客是选择参与拍卖、还是选择以固定价格购买主要依赖于顾客到达拍卖时距离拍卖结束的剩余时间.最后,通过算例,我们对影响顾客参与策略的因素进行了数值分析并得到了一些结论.     

佣金收取对拍卖结果的影响

在引入佣金提成的独立私人价值模型及关联价值模型中,讨论第一价格和第二价格拍 卖,发现佣金比例k 的大小对投标人的出价策略、卖方和拍卖行的期望收益都有影响. k 越大, 买方出价越谨慎,卖方的期望收益更少,拍卖行的期望收益却更大. 虽然买方会随着k 的增大 出价更谨慎,但均衡期望收益却与k 无关. 在独立私人价值模型中,当引入佣金时,收益等价 性仍然成立. 这对拍卖实践提供了建议:投标人(买方) 对于佣金比例高低的担忧是多余的     

考虑竞争者进入威胁的易逝品动态定价机制

本文研究了同时考虑竞争者进入威胁和消费者行为的易逝品的动态定价机制.依据策略性和忠诚性两个维度,将市场中的消费者分为策略型忠诚者、策略型转换者、短视型忠诚者和短视型转换者四种类型.建立了在位企业、竞争企业与策略消费者间的两阶段动态博弈模型,通过均衡求解与分析,探讨了在位企业和竞争企业的最优价格机制以及消费者行为对企业定价行为和均衡收益的影响,深入分析了竞争者的进入行为对在位企业定价和收益的影响,以及消费者策略行为和转换行为与竞争者进入行为间的交互作用机制.研究表明:在位企业可以依据策略消费者的比例,采取智能的动态定价机制,实行或放弃对策略消费者的跨期价格歧视,最大化自身收益;消费者策略行为会降低在位企业的绩效却能够提高竞争者的绩效;竞争者的进入并非总是对在位企业不利,在一定条件下,竞争者的进入有利于提高在位企业的绩效;在位企业通过多种方式培养自己的忠实顾客,不仅能够应对竞争者的进入威胁而且能够缓解消费者策略行为的负面影响.     

非对称情况下的多物品拍卖

本文讨论当投标人之间存在不同的预算约束时两物品的序贯增价拍卖,对于物品之间不同的关系(互补、替代或者不相干的关系),物品价值大小的不同及与预算大小之间的关系,在一个简单的完全信息模型下,我们分不同情况讨论投标人的均衡出价策略,并发现对卖方来说,先拍卖价值高的物品是弱占优的策略。     

Design of Auction Parameters to Reduce the Effect of Collusion

Government departments are increasingly turning to auctions to procure goods and services. Collusion among bidders, however, reduces competition and raises winning bid prices. Since conventional collusion control measures based on the redesign of auction mechanisms are less effective in government procurement auctions, there is a need to devise control measures that decrease the effect of collusion. This article demonstrates how the principles of design of experiments can be applied in a system dynamics model to find the auction parameter values that substantially reduce the effect of collusion in government procurement auctions. This research makes a number of contributions. First, it develops a feedback‐based dynamic mechanism of collusion in government procurement auctions. The mechanism proposes the winning bid price as being determined not by the total number of bidders but by the number of independent bidders. It defines each cartel as one independent bidder regardless of the number of bidders in the cartel. Second, the mechanism is tested by developing a system dynamics model to government auctions for procuring contracts for roadwork projects in India. Third, the principles of experimental design are applied to find the auction parameter values that ensure high bid participation and low winning price‐to‐reserve price ratios.     

Collusion in Second‐Price Auctions under Minimax Regret Criterion

Collusion in auctions, with different assumptions on distributions of bidders' private valuation, has been studied extensively over the years. With the recent development of on‐line markets, auctions are becoming an increasingly popular procurement method. The emergence of Internet marketplaces makes auction participation much easier and more convenient, since no physical presence of bidders is required. In addition, bidders in on‐line auctions can easily switch their identities. Thus, it may very well happen that the bidders in an auction have very little, if any, prior knowledge about the distributions of other bidders' valuations. We are proposing an efficient distribution of collusive profit for second‐price sealed bid auctions in such an environment. Unlike some known mechanism, which balance the budget only in expectation, our approach (which we call Random k) balances the budget ex‐post. While truth‐telling is not a dominant strategy for Random k, it is a minimax regret equilibrium.     

考虑消费者细分的网购拼单机制研究

本文提供理论模型分析网购拼单机制分别给销售者和消费者带来的影响，为销售者（消费者）的抉择提供参考。研究结果显示，当拼单价格和正常价格均很低时，销售者（消费者）无动机实施（参与）拼单机制。但随着正常价格的提高，拼单机制的营利能力（消费者剩余）会不断增大，进而激励销售者（消费者）实施（参与）拼单机制，并有会将低估价类型消费者驱逐出市场。这一结果从另一个方面反映了拼单机制的最终目标不是为了迎合低估价类型的消费者，而是为了吸引高估价类型的消费者参与交易。进一步地，在拼单机制有效实施的情形下，最优拼单数量、最优期望收益均与两种类型消费者估值比例密切相关。所以，在实施拼单机制过程中，应该有意识地对消费者进行细分，并挖掘不同类型消费者的私人信息，从而制定有效的拼单策略。     

On the Existence of Pure Strategy Monotone Equilibria in Asymmetric First‐Price Auctions

We establish the existence of pure strategy equilibria in monotone bidding functions in first‐price auctions with asymmetric bidders, interdependent values, and affiliated one‐dimensional signals. By extending a monotonicity result due to Milgrom and Weber (1982), we show that single crossing can fail only when ties occur at winning bids or when bids are individually irrational. We avoid these problems by considering limits of ever finer finite bid sets such that no two bidders have a common serious bid, and by recalling that single crossing is needed only at individually rational bids. Two examples suggest that our results cannot be extended to multidimensional signals or to second‐price auctions.     

Increasing Revenue by Decreasing Information in Procurement Auctions

We report on results of several laboratory experiments that investigate on‐line procurement auctions in which suppliers bid on price, but exogenous bidder quality affects winner determination. In procurement auctions, bidder quality may or may not be publicly known to all bidders, and the effect of this quality transparency on the auction outcome is one aspect of auction design that we examine. The second aspect of auction design that we examine is the effect of price visibility on the auction outcome, and the interaction between price visibility and quality transparency. In terms of price visibility, we consider two extreme cases: the sealed bid request for proposals (RFPs), and the open‐bid dynamic auction event. In terms of bidder quality transparency, we also consider two extreme cases: a setting in which bidder qualities are publicly known and the case in which they are private. We find that in our laboratory experiments, the RFP format is consistent in generating higher buyer surplus levels than does the open‐bid dynamic format. This advantage is independent of the quality transparency. In contrast, the open‐bid format is highly sensitive to quality transparency, generating significantly lower buyer surplus levels when the information about bidder quality is public.     

Ranked Items Auctions and Online Advertisement

We study auctions for a set of commonly‐ranked items where each buyer has unit demand. This setting has promising applications in areas such as keyword auctions in the search engine advertising industry, the sale of quality‐ranked raw materials, etc. An auction mechanism suitable for this setting is the simultaneous pooled auction (SPA), where each bidder simultaneously submits a single bid and is allocated an object based on the rank of his bid among all the bids. We study how to improve the seller's expected revenue by enforcing a reserve price in an SPA. We find that the use of an appropriate reserve price may significantly increase the seller's revenue, especially when the number of items for sale is relatively large compared to the number of participating bidders. One inherent problem in the SPA is that some bidders may incur ex post losses; that is, they pay more than what they value the received objects. We propose a tailored VCG mechanism that generates the same expected revenue as the SPA does, while bidders do not incur any ex post loss. We also discuss the potential applications of this research to keyword auctions.     

在线拍卖中的“托”出价研究

本文分析了独立的私人估价环境下最优保留价格与竞买人数之间的关系,纠正了最优保留价格与竞买人数无关的传统观点.在此基础上,讨论了卖者可能递交"托"出价的条件以及拍卖中只剩下一个竞买人时卖者的最优"托"出价.