两阶段网上相继起拍拍卖中最优拍卖策略研究

基于序贯拍卖和同时向上叫价拍卖的特点,本文首先提出了网上相继起拍拍卖模式,建立了两阶段相继起拍拍卖模型;在允许缺货的条件下,分析了卖方最优拍卖策略的一些性质,给出了卖方总期望收益的上下限;最后,对影响卖方最优拍卖策略的因素进行了数值分析,得到在某些情况下卖方在第二场拍卖开始时根据当前库存量以及已参与第一场拍卖的顾客数采用缺货策略可以提高卖方期望收益等结论。     

基于幂效用函数的多属性英式拍卖研究

以采购问题为背景研究多属性拍卖问题,其中拍卖问题的特点是：（1）包含任意有限个属性;（2）买卖双方的效用函数均具有加性结构,且在除价格以外的单个属性上,买方的效用函数和卖方的成本函数均为一般幂函数形式。首先,设计了一种买方事先公布评分函数而卖方轮流提交投标的多属性英式拍卖机制;其次,在卖方对称的假设下分析了拍卖机制中的最优投标策略,确定了最优投标价格和最优非价格属性值;然后,分析得出了最具成本优势的卖方最终胜出的条件以及最优多属性投标;最后,计算了该拍卖机制中买方的期望收益,并求出了使其期望收益最大化的最优评分函数权重。     

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.     

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     

考虑佣金的关联价值拍卖模型

在标准的只考虑买卖双方的拍卖模型中引入第三方,拍卖公司.拍卖公司提供服务要收取一定的佣金,佣金费用由买家支付,支付额占成交价的比例为k.文章发现,佣金比例k的大小对买卖双方均有一定影响:买方的出价策略变得谨慎但是其均衡期望收益却与k无关;卖方的期望收益受到影响而降低.事实上,拍卖公司的佣金就是来自于卖方的期望收益中.文中就第一价格与第二价格机制在关联价值模型上讨论佣金问题,得到的结果有较普遍的意义.     

考虑供应风险和生产成本不确定性的供应链动态决策研究

考虑到供应风险和生产成本的不确定性,本文研究了买方或卖方实施努力既可能改善供应可靠性,同时又可能降低生产成本的供应链最优决策问题。分别构建了制造商努力和供应商努力的两阶段动态决策模型。分析了提升供应可靠性和降低成本的概率对两种模型中的最优采购数量、最优努力程度和上下游期望收益以及供应链期望收益的影响。同时在两种模型的比较中发现,制造商的最优努力与供应商的最优努力之间的差异与收益分享系数有关。相同努力效果下,制造商努力时的最优采购数量总是不小于供应商努力时的最优采购数量。相比供应商努力,制造商努力更有利于增加其自身的期望收益。然而,供应商以及整个供应链的期望收益却可能在供应商努力时更高。     

肯德基“秒杀”信任危机

肯德基深陷“秒杀门”早已经满城风雨，一方有理有据，另一方坚持认定对方“商业欺诈”，孰对孰错也难做讨论。然而面对纷纷质疑，舆论几乎“一边倒”的认定肯德基失信，对方的解释也难以令人信服。事态的升级往往伴随难以收尾的恶果，在舆论普遍以“究竟谁秒杀了谁”作为疑问发声的时候，很多人都会理所当然的以为，肯德基走了霉运，然而事实是这样吗？     

拍卖中的串通出价

本文在扩展的独立私有价值模型下,考虑第二价格和第一价格拍卖机制下的串通出价行为和卖方对串通出价的反映。第二价格串通出价机制和第一价格串通出价机制分别为在这两种拍卖机制下的激励相容、有效的直接显示串通出价机制。我们发现卖方若知道有串通行为,可以提高保留价来减少损失。由于卖方一般情况下不太可能确定是否存在串通行为及参与串通的人数k,但可以确定给定保留价时串通人数的'最优反应',在第二价格串通出价机制下,给定串通人数,增加保留价可以提高卖方的期望收益,对于确定的保留价,串通人数的增加会减少卖方的期望收益。从而存在这样的纳什均衡:所有的投标人串通,即,k=N,而卖方宣布与之相应的保留价r (N)。当然,并不是所有的串通出价对投标人都是有利可图的,在第一价格拍卖机制下,若卖方可以调整保留价,只有当参与竞投的人很多时,串通出价才有利可图。     

带佣金率和保留价的一级和二级价格拍卖

本文通过引入佣金率和保留价,分别讨论了一级和二级价格密封式拍卖,得到以下结论:(1)两种密封式拍卖的均衡报价随佣金率的提高而减少;(2)一级价格密封式拍卖的均衡报价随保留价的增加而增加,而二级价格密封式拍卖的均衡报价随保留价的增加而减少;(3)一级价格密封式拍卖的投标者预期收益与佣金率和保留价均呈反向变动,而二级价格密封式拍卖的投标者预期收益独立于佣金率和保留价;(4)收益等价定理仍然成立;(5)在两种密封式拍卖中,当佣金率增加时,卖方的预期收益减少,拍卖行的预期收益以及卖方和拍卖行的总预期收益可能增加也可能减少;(6)在两种密封式拍卖中,当保留价增加时,卖方的预期收益、拍卖行的预期收益以及卖方和拍卖行的总预期收益可能增加也可能减少;(7)给出了卖方的最优保留价的表达式;(8)把本文的结论与以前相应的研究工作做了比较。     

基于双边减排成本信息不对称的排污权二级交易市场拍卖机制研究

本文构建了一个基于双边减排成本信息不对称的排污权二级交易市场拍卖模型,分析了统一价格、歧视价格及混合拍卖机制下卖方收益、排污权价格波动及排污权供给量差异,在此基础上给出了排污权二级交易市场最优拍卖机制,并进一步讨论了相关参数对最优拍卖机制的影响。结果表明：从收益最大化角度来看,最优的拍卖机制为歧视价格拍卖机制,但考虑到价格波动及排污权供给量等其他因素,排污权二级市场交易应选用混合拍卖机制。风险偏好变化对混合拍卖机制下卖方收益及价格波动的影响存在不确定性,当风险偏好超过某一阈值时,随着风险偏好程度增大,需求隐蔽效应占主导,收益及价格波动增大;相反,当风险偏好小于某一阈值时,随着风险偏好程度增大,竞争效应占主导,收益及价格波动减小。价格变动的供给影响系数对卖方收益的影响随买方参与人数的不同而不同。当买方参与人数较小时,需求隐蔽效应占主导,竞争效应不明显,随着价格变动的供给影响系数增大,混合拍卖机制下卖方的收益不断增加;当买方参与人数较大时,卖方收益同时受到需求隐蔽和竞争效应影响,随着价格变动的供给影响系数增大,收益呈先增大后减小趋势。随着价格变动的供给影响系数增大,价格波动呈先增大后减小趋势。     

Split‐Award Procurement Auctions—Can Bayesian Equilibrium Strategies Predict Human Bidding Behavior in Multi‐Object Auctions?

We analyze if and when symmetric Bayes Nash equilibrium predictions can explain human bidding behavior in multi‐object auctions. We focus on two sealed‐bid split‐award auctions with ex ante split decisions as they can be regularly found in procurement practice. These auction formats are straightforward multi‐object extensions of the first‐price sealed‐bid auction. We derive the risk‐neutral symmetric Bayes Nash equilibrium strategies and find that, although the two auction mechanisms yield the same expected costs to the buyer, other aspects of the two models, including the equilibrium bidding strategies, differ significantly. The strategic considerations in these auction formats are more involved than in single‐lot first‐price sealed‐bid auctions, and it is questionable whether expected utility maximization can explain human bidding behavior in such multi‐object auctions. Therefore, we analyzed the predictive accuracy of our equilibrium strategies in the laboratory. In human subject experiments we found underbidding, which is in line with earlier experiments on single‐lot first‐price sealed‐bid auctions. To control for regret, we organize experiments against computerized bidders, who play the equilibrium strategy. In computerized experiments where bid functions are only used in a single auction, we found significant underbidding on low‐cost draws. In experiments where the bid function is reused in 100 auctions, we could also control effectively for risk aversion, and there is no significant difference of the average bidding behavior and the risk‐neutral Bayes Nash equilibrium bid function. The results suggest that strategic complexity does not serve as an explanation for underbidding in split‐award procurement auctions, but risk aversion does have a significant impact.     

Bidding under auctioneer default risk

In a financially turbulent economy, participants of a procurement auction should consider in their bids the event of default of the auctioneer, which may result to substantial damages for the winning bidder. We examine a sealed bid auction, with private cost values and interdependence among the beliefs of the bidders about the auctioneer׳s default risk. The probability of payment of the bid price by the auctioneer is estimated by each bidder. For a first and a second price auction, we derive equilibrium bidding strategies, which address the risk of default and optimally adjust the bid price, introducing a risk premium in the form of an additional mark-up. A numerical illustration of the proposed strategies is provided. The effect of auctioneer׳s risk of default on the procurement project cost is examined. Financial arrangements that may be used to relax or eliminate the effect of the risk of default, such as early payment methods, third party guarantees or insurance programs are discussed and evaluated in comparison with the approach of risk premium on bid price.     

一种信息优势的比较和拍卖机制研究

以目前网上拍卖和多物品拍卖为背景,从"信息优势"的角度研究了一个拍卖信息从隐藏、部分隐藏、逐步过渡为公开等5种具体情形的两异质物品序贯拍卖问题,分析和比较了各种情形下竞标人的占优报价和拍卖方的期望收入,探讨了信息优势对估价和拍卖效率的影响,得到了一些有关拍卖机制设计和信息策略选择的有价值结论,并结合网上拍卖和招投标管理等给出了相关机制设计的建议.     

Do Auction Parameters Affect Buyer Surplus in E‐Auctions for Procurement?

Although the initial euphoria about Internet‐enabled reverse auctions has given way to a cautious but widespread use of reverse auctions in business‐to‐business (B2B) procurement, there is a limited understanding of the effect of auction design parameters on buyer surplus. In this paper, we study the effect of bidding competition, information asymmetry, reserve price, bid decrement, auction duration, and bidder type on buyer surplus. We collected field data on more than 700 online procurement auctions conducted by a leading auctioneer and involving procurement items worth millions of dollars. Consistent with the predictions of auction theory, the results indicate that bidding competition, reserve price, and information sharing affect buyer surplus. Unlike previous findings in the consumer‐to‐consumer context, we find that bid decrement and auction duration have no effect in B2B procurement auctions. Our results suggest that use of the rank‐bidding format increases buyer surplus when incumbent suppliers participate in the auction. We discuss the theoretical and managerial implications of these findings for future research and for optimal design of online procurement auctions.     

Keyword Auctions,Unit‐Price Contracts,and the Role of Commitment

Motivated by the enormous growth of keyword advertising, this paper explores the design of performance‐based unit‐price contract auctions, in which bidders bid their unit prices and the winner is chosen based on both their bids and performance levels. The previous literature on unit‐price contract auctions usually considers a static case where bidders' performance levels are fixed. This paper studies a dynamic setting in which bidders with a low performance level can improve their performance at a certain cost. We examine the effect of the performance‐based allocation on overall bidder performance, auction efficiency, and the auctioneer's revenue, and derive the revenue‐maximizing and efficient policies accordingly. Moreover, the possible upgrade in bidders' performance level gives the auctioneer an incentive to modify the auction rules over time, as is confirmed by the practice of Yahoo! and Google. We thus compare the auctioneer's revenue‐maximizing policies when she is fully committed to the auction rule and when she is not, and show that the auctioneer should give less preferential treatment to low‐performance bidders when she is fully committed.     

增价拍卖中投标者跳跃报价的收益效应研究

跳跃投标是增价拍卖一种普遍现象,而跳跃投标是否会带来投标方的期望收益的增加是一个值得关注的问题。通过运用博弈论方法,分别寻找单物品和多物品拍卖两种情形下的跳跃报价均衡,计算出跳跃报价均衡下的投标方期望收益,并将其结果与非跳跃报价情形进行比较,给出了投标方希望通过跳跃出价改善其期望收益的一般条件。     

Behavior in Multi‐Unit Demand Auctions: Experiments with Uniform Price and Dynamic Vickrey Auctions

We experimentally investigate the sensitivity of bidders demanding multiple units of a homogeneous commodity to the demand reduction incentives inherent in uniform price auctions. There is substantial demand reduction in both sealed bid and ascending price clock auctions with feedback regarding rivals' drop‐out prices. Although both auctions have the same normal form representation, bidding is much closer to equilibrium in the ascending price auctions. We explore the behavioral process underlying these differences along with dynamic Vickrey auctions designed to eliminate the inefficiencies resulting from demand reduction in the uniform price auctions.