付费搜索拍卖建模与两类排名机制比较研究

在综合付费搜索拍卖静态博弈研究成果的基础上,通过归纳广告主估价函数结构和梳理拍卖规则,建立了较为一般性的付费搜索拍卖模型,定义了GSP机制下付费搜索拍卖的纳什均衡条件和无嫉妒均衡条件并阐述了二者之间的关系,证明了有效竞价排名相对于单纯竞价排名具有更好的均衡配置效率,但是不能保证搜索引擎收益一定得到提高,最后通过数值分析进一步指出,只有广告主相关度因子存在较大差别时,有效竞价排名相对于单纯竞价排名的优势才能得以体现。     

The 2007 Subprime Market Crisis Through the Lens of European Central Bank Auctions for Short‐Term Funds

We study European banks' demand for short‐term funds (liquidity) during the summer 2007 subprime market crisis. We use bidding data from the European Central Bank's auctions for one‐week loans, their main channel of monetary policy implementation. Our analysis provides a high‐frequency, disaggregated perspective on the 2007 crisis, which was previously studied through comparisons of collateralized and uncollateralized interbank money market rates which do not capture the heterogeneous impact of the crisis on individual banks. Through a model of bidding, we show that banks' bids reflect their cost of obtaining short‐term funds elsewhere (e.g., in the interbank market) as well as a strategic response to other bidders. The strategic response is empirically important: while a naïve interpretation of the raw bidding data may suggest that virtually all banks suffered an increase in the cost of short‐term funding, we find that, for about one third of the banks, the change in bidding behavior was simply a strategic response. We also find considerable heterogeneity in the short‐term funding costs among banks: for over one third of the bidders, funding costs increased by more than 20 basis points, and funding costs vary widely with respect to the country‐of‐origin. The funding costs we estimate using bidding data are also predictive of market‐ and accounting‐based measures of bank performance, reinforcing the usefulness of “revealed preference” information contained in bids.     

Generalized Reduced‐Form Auctions: A Network‐Flow Approach

We develop a network‐flow approach for characterizing interim‐allocation rules that can be implemented by ex post allocations. Our method can be used to characterize feasible interim allocations in general multi‐unit auctions where agents face capacity constraints, both ceilings and floors. Applications include a variety of settings of practical interest, ranging from individual and group‐specific capacity constraints, set‐aside sale, partnership dissolution, and government license reallocation.     

Transparency in Buyer‐Determined Auctions: Should Quality be Private or Public?

We study buyer‐determined procurement auctions where both price and non‐price characteristics of bidders matter for being awarded a contract. Although, in scoring auctions bidders perfectly know how price and non‐price attributes determine the awarding of the contract, this remains uncertain in buyer‐determined auctions where the buyer is free to choose once all bids have been submitted. We analyze the impact of information bidders have with respect to the buyer's awarding decision. As we show theoretically whether it is in the buyer's interest to conceal the impact of non‐price characteristics depends on how important the quality aspects of the procured good are to the buyer: The more important quality aspects are, the more interesting concealment becomes. In a counterfactual analysis using data from a large European procurement platform, we analyze the reduction of non‐price information available to the bidders. Confirming our hypothesis, for auction categories where bidders’ non‐price characteristics strongly influence buyers’ decisions concealment of non‐price information leads to an increase in buyers’ surplus of up to 15% due to higher competitive pressure and lower bids. Conversely, for categories where bidders’ non‐price characteristics are of little importance concealment of non‐price information leads to a decrease in buyers’ surplus of up to 6%.     

拍卖采购合同及议价谈判机制设计

考虑采购商在多个潜在供应商中选择1名获胜者来提供单物品或服务,并且供应商存在不可见努力的情况,设计了两阶段采购机制.该机制先实施关于合同的拍卖阶段,再执行可能的议价谈判阶段.分析的基本结论是,在对称信息情况下,存在系统最优的质量标准和努力水平;不对称信息下,投标者将在拍卖阶段报价自己的真实成本.在不对称信息的谈判阶段,存在包含重新确定的价格、质量和努力水平的惟一议价均衡,此均衡将实现对称信息下的分配效率——系统最优.从采购商的利益出发,给出了采购商选择采取谈判策略或者采用拍卖阶段合同的条件.     

Contractors’ and Agency Decisions and Policy Implications in A+B Bidding

The focus of this study is on the A+B transportation procurement mechanism, which uses the proposed cost (A component) and the proposed time (B component) to score contractors’ bids. Empirical studies have shown that this mechanism shortens project durations. We use normative models to study the effect of certain discretionary parameters set by state transportation agencies on contractors’ equilibrium bidding strategies, winner selection, and actual completion times. We model the bidding environment in detail including multi‐dimensional bids, contractors’ uncertainty about completion times, and reputation cost. The latter refers to a private penalty that accrues to tardy contractors from increased cost of posting bonds and reduced prospects of winning future projects. Our model explains why contractors may skew line‐item bids and why winners frequently finish earlier than bid. It has several policy implications as well. For example, we recommend that agencies set the daily incentive, disincentive, and road user cost to be equal and not cap incentives. This is a departure from current practice, where incentives are often capped and weaker than penalties. Furthermore, we show that agencies may be justified in setting daily road user cost strictly smaller than the true cost of traffic disruption during construction.     

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。     

考虑再谈判的网上服务采购多属性拍卖研究

针对在线服务外包,研究了供应商投标服务方案(体现服务质量)和价格的买方决定制多属性采购拍卖,分析了交易双方关于服务内容的再谈判对供应商投标均衡、买方初始服务内容决策和各方期望利润的影响。结果表明,无再谈判情形下,供应商的服务质量投标均衡和信息租金都随初始服务内容递增;而有再谈判情形下,尽管买方对服务质量的评标权重随初始服务内容递增,但供应商服务质量、信息租金及买方期望利润都不受初始服务内容影响。换言之,初始服务内容对采购项目的规制作用被再谈判完全替代。不仅如此,相较于无再谈判情形,再谈判的存在能够激励供应商提供更高的服务质量,并促成更多的服务内容成交,最终使买方、获胜供应商和交易平台都获得更高期望利润。     

Explaining and Forecasting Online Auction Prices and Their Dynamics Using Functional Data Analysis

Online auctions have become increasingly popular in recent years, and as a consequence there is a growing body of empirical research on this topic. Most of that research treats data from online auctions as cross-sectional, and consequently ignores the changing dynamics that occur during an auction. In this article we take a different look at online auctions and propose to study an auction's price evolution and associated price dynamics. Specifically, we develop a dynamic forecasting system to predict the price of an ongoing auction. By dynamic, we mean that the model can predict the price of an auction “in progress” and can update its prediction based on newly arriving information. Forecasting price in online auctions is challenging because traditional forecasting methods cannot adequately account for two features of online auction data: (1) the unequal spacing of bids and (2) the changing dynamics of price and bidding throughout the auction. Our dynamic forecasting model accounts for these special features by using modern functional data analysis techniques. Specifically, we estimate an auction's price velocity and acceleration and use these dynamics, together with other auction-related information, to develop a dynamic functional forecasting model. We also use the functional context to systematically describe the empirical regularities of auction dynamics. We apply our method to a novel set of Harry Potter and Microsoft Xbox data and show that our forecasting model outperforms traditional methods.     

Electronic Markets for Truckload Transportation

A wide variety of electronic marketplace formats are used in the Truckload (TL) transportation industry, including combinatorial auctions, private and public exchanges, and electronic catalogs. Combinatorial multi‐attribute auctions are commonly used strategically to populate electronic catalogs, commonly called “routing guides,” with pricing, assignments, and priority logic. Private and public exchanges are used to complement the electronic catalogs in cases where the catalog fails. This paper discusses the TL transportation market, places the procurement of services in the context of electronic marketplace formats, and illustrates how these are currently used.