【作者】 杨兴丽；

【导师】 吕廷杰；

【作者基本信息】 北京邮电大学 ， 管理科学与工程， 2008， 博士

【摘要】 伴随着互联网的诞生,网上拍卖变得炙手可热。网上拍卖的短短历史与其飞速发展相比,存在极大的差异,引起了专家和学者们的极大关注。这就为对于想了解在实践中使用各种交易机制的经济学家提供了丰富的研究课题,同时也为各种经济理论提供了理想的实验基地。这就使得对网上拍卖理论的研究势在必行。本文以网上拍卖为背景,以传统拍卖理论、博弈论以及概率论和其他的数学知识作为研究工具,对网上拍卖中新出现的一种拍卖方式——一口价网上英式拍卖进行了研究,并且对网上最后一分钟竞价也进行了深入的剖析。主要内容可概括如下几个方面:1、与传统拍卖相比,网上拍卖模式不断创新。网上一口价拍卖作为网上拍卖的创新模式,由于打破了固定拍卖结束时间的局限,而得到广泛应用。其中在众多模式中比较典型的网上一口价拍卖模式有三种,分别是固定一口价、临时一口价和持久一口价。投标者的决策决定了拍卖的最终结果,也是拍卖理论研究的重点之一。在独立的私有估价模型下,采用在固定一口价拍卖方式,估价高于一口价的投标者的最优选择是及早选择一口价;在临时一口价中存在一个均衡点,使得估价高于此均衡点的投标者及早选择一口价是最优的;持久一口价中存在一个临界函数和一个均衡点,使得估价满足临界函数或高于均衡点的投标者及早选择一口价是最优的。2在关联估价模型下,由于投标者之间的相互影响,不存在最优策略选择。采用在固定一口价拍卖方式,估价高于一口价的投标者不再立即选择一口价,而是观望确认其他的投标者的信息,迟投标是比较明智的选择;在临时一口价中依然存在一个均衡点,均衡点的确定受到其他投标者信息的影响,并且估价高于均衡点的投标者不会立即选择一口价;持久一口价中存在一个临界函数和一个均衡点,它们同样受到其他投标者信息的影响,使得估价满足临界函数或高于均衡点的投标者也不能立即选择一口价。比较在独立私有价值和关联价值模型下的三种一口价拍卖方式的投标策略,发现产生了很大的变化,对此进行分析。3、从卖家的角度来说,选择什么样的一口价拍卖方式能使自己的收益获得最大,是一个重要的考虑因素。所以卖家在决定采用哪种一口价拍卖方式后,面临设定合适的一口价拍卖的参数——一口价(一口价的优化),以便获取最大的收益。在本文中我们分别讨论了三种一口价拍卖方式中一口价的优化问题,进而在已经设置好的最优一口价下,分析三种不同一口价拍卖方式中卖家的收益问题。在独立私有估价模型下设置相同的一口价时,三种一口价拍卖方式的收益如何?通过数值比对,得出结论:临时一口价的收益最大,持久一口价次之,固定一口价最小。最后以固定一口价为例得到,随着一口价的增加,卖家收益随之增加,直到最优的一口价,卖家的收益随之减小;随着一口价的增加,物品的非成交概率增加;卖家的收益随着参与顾客人数的增加而增加。4、最后一分钟竞价在网上拍卖中的流行引起了人们的极大关注,一些学者通过不同的角度对此进行了研究,取得了一定的成果。本文中,我们对采用不同拍卖结束规则的拍卖方式下的投标策略,分别在独立私有估价模型和关联估价模型下进行了分析,得出结论:在独立私有估价模型下,采用“硬规则”的拍卖中更容易发生狙击现象,而采用“软规则”的拍卖中,不易发生狙击现象;在关联估价模型下,采用“硬规则”的拍卖中,有更多专业知识的或经验丰富的投标者会选择最后时刻投标;而采用“软规则”的拍卖中,有更多专业知识的或经验丰富的投标者不会获胜。而后对于采用不同拍卖结束规则的拍卖收益进行了分析,在采用“硬规则”的拍卖中,买方可以采用最后时刻投标的策略得到更多额外的收益,这样卖家的期望收益受损;在采用“软规则”的拍卖中,买方只能根据自己的估价进行竞价,不能得到更多的额外收益,卖家的收益由于可以将物品卖给估价最高的投标者而实现收益最大化。更多还原

【Abstract】 Along with the inception of the Internet, Online auctions have become popular. There will be a lot of contrasts compared online auction with a short history with its rapid development, which made great concern to experts and scholars of. A rich source of research topics are suggested for economists who would like to know the use of various trading mechanisms in practice. Online auction provides the ideal experimental site for various economic theories as well. It makes the research about online auction theory inevitable. Based on online auction, we take the traditional auction theory, game theory, and probability theory and other mathematical knowledge as a research tool to study of a new online auction, buyout price English auction. And we also make in-depth analysis about the last-minute bidding. Main contents can be summarized in the following aspects:1 Compared with traditional auctions, online auctions make mode of innovation continuously. Online auctions with buyout price, as a mode of the online auction innovation, are widely used because of breaking the auction end of fixed time limits. There are several online auctions with buyout price, and three of them are typical. They are fixed buyout price, temporary buyout price and permanent buyout price respectively. Bidders’ strategies decide the ultimate outcome of the auction, which are one of the research emphases of auction theory. Under the independent private valuation model the optimal choice of the bidder with higher valuation than buyout price is to use the buyout price option early in fixed buyout price auction; there is an equilibrium which makes the bidder with higher valuation than the equilibrium use the buyout price option in temporary buyout price auction; threshold function and an equilibrium are existed in permanent buyout price auction, in which the optimal choice of the bidder with higher valuation than the equilibrium or valuation meeting the threshold function is to use the option of buyout price.2 Under the affiliated valuation model, there is no choice of the optimal strategy because of the interplay among the bidders. Bidders with higher valuation than buyout price do not immediately choose a buyout price option, but they wait-and-see to get the other bidders’ information, so late bidding is the wiser choice in fixed buyout price auction; there is a still equilibrium in temporary buyout price auction, and the determination of equilibrium is affected by the other bidders’ information, and the bidder with higher valuation than the equilibrium does not use the option of the buyout price; in permanent buyout price auction there are threshold function and equilibrium that are affected by the other bidders’ information, so the bidder who has the valuation meeting the threshold function or higher valuation than the equilibrium can’t choose the buyout price option. Compared with the bidders’ strategies in three auctions with buyout price which are under different models: the independent private valuation model and the affiliated valuation model, we find a great deal of change, and then analyze it.3 From the viewpoint of seller, the choice of what kind of a buyout price auction to make itself the greatest benefits is an important consideration. So after the seller deciding to adopt a buyout price auction, he face a question about setting a suitable parameter of the auction-- buyout price, that is the optimization of the buyout price, to obtain the max utility. In our dissertation we discuss the optimization problem of buyout price in the three different auctions with buyout price. And then we analyze the seller’s profit under the optimal buyout price respectively. How will the profit in the three different auctions with buyout price under the independent private model? After the numerical analysis we conclude: the profit of temporary buyout price is the biggest, permanent buyout price second, and the final is the fixed buyout price. Finally, we use fixed buyout price English auction as an example and get some conclusions. With the buyout price increasing, the seller’s revenue is increasing. Until the optimal buyout price, the seller’s revenue is declining. With the buyout price increasing, the probability of non-transaction goods is increasing. With the number of customers increasing, the seller’s revenue is increasing.4 The popular of last-minute bidding in online auctions arouse great concern to the people. Some scholars do researches through different point, and then they achieve certain results. In the dissertation we study the bidders’ strategies in different end rules under the independent private model and affiliated valuation model respectively. The conclusions are: the sniping is more easily appeared in the auction with "hard" end rule, but does not in the auction with "soft" end rule under the independent private model. The bidders with more informed knowledge and experience choose to bid at the last moment in "hard" end rule, but they will not win in "soft" end rule under affiliated valuation model. Then we study the auction revenue in different auction end rules. The buyers can obtain more additional revenue through the method of bidding at the last moment in the auction with "hard" rule, then the seller’s expected profit is damaged. In the auction with "soft" rule the buyers can only bid according to their valuation and can not obtain the additional revenue. So the seller’s profit can be maximized because of the object being given the bidder who has the biggest valuation.更多还原