Online Auction Fraud: Ethical Perspective

Internet fraud is an issue that increasingly concerns regulators, consumers, firms, and business ethics researchers. In this article, we examine one common form of internet fraud, the practice of shill bidding (when a seller in an auction enters a bid on his or her own item). The significant incidence of shill bidding on eBay (in spite of the fact that it is illegal just as it is in live auctions) exemplifies the current ineffectiveness of regulatory means as well as the lack of effective societal mechanisms to prevent online fraud. Further, the proliferation of shill bidding along with other types of internet fraud may have broader implications. If unethical behavior such as shill bidding becomes too widespread on the internet, regulators and other societal forces may deem it necessary to institute controls that will impact the entire online marketplace as well as the future development and regulation of business activities on the internet. Our results indicate that shill bidding is perpetrated on eBay significantly more often than 0.1% rate of fraud estimated by the firm. This suggests that regulators, users, and others stakeholders may become concerned enough to act. The impact of those responses on the internet of the future may affect a broad array of users beyond the unethical sellers on eBay. Alex Nikitkov is an Assistant Professor of Accounting at Brock University in St. Catharines, Ontario, Canada Darlene Bay is an Assistant Professor of Accounting at Brock University in St. Catharines, Ontario, Canada     

在线拍卖市场信任机制构建的研究

随着在线拍卖市场的迅速发展,在线拍卖欺诈也越来越严重.因此,如何防止或减少在线拍卖欺诈是在线拍卖设计必须考虑的一个重要方面.本文通过对在线拍卖市场的博弈分析,给出了第三方认证机制的设计.该机制的目的是在在线拍卖环境中建立信任,通过信誉的使用帮助减少在线拍卖的欺诈行为.这一机制结合了在线业务的经济和技术方面,它采用了经济激励方式来说明信誉是如何被用来有效制止欺诈行为.     

在线拍卖诚信行为的博弈分析

在线拍卖交易中双方的不诚信行为已经成为制约在线拍卖交易发展的一个重要因素,为此,有必要应用博弈论的有关方法对在线拍卖交易双方的诚信行为进行分析研究,构建在线拍卖信用评价机制,这样在一定程度上保证了在线交易的安全,为政府监督在线拍卖交易提供有力的支持。     

我国期货市场的波动性与有效性--基于三大交易市场的实证分析

通过对中国三大期货市场的铜、黄豆和小麦三种主要期货品种收益率的分布与波动性的实证分析 ,论证了其时间序列存在ARCH效应 ;运用GARCH模型对这三种期货品种进行了拟合分析和统计检验 ,检验结果表明这三个期货品种的波动性均具有很高的持续性 ,但大连黄豆的波动持续性弱于上海铜和郑州小麦 ,其波动性受各种外部冲击的影响较大 ;通过GARCH( 1 ,1 )的市场有效性检验 ,论证了中国期货市场尚未达到弱式有效 ,市场风险较大。     

Changes in the options contract size and arbitrage opportunities

We examine the impacts of changes to the options multiplier on market efficiency by analyzing their effects on arbitrage proxies based on the performance of options spread strategies. Despite the intentions of the reforms, both decisions to raise and reduce the multiplier significantly increase the frequency and probability of arbitrage opportunities. Whereas the increment in the multiplier also deteriorates market efficiency by increasing the duration and average size of the arbitrage opportunities in a day, the decrement does not affect these proxies. Our results overall provide evidence that reforms to the options multiplier do not enhance market efficiency and suggest that retail investors are not homogeneously noisy.     

市场势力对初始排污权拍卖效率和收益的影响

从市场势力角度入手,运用市场势力相关理论,分析现有市场势力对初始排污权拍卖效率和收益的影响,认为市场势力会加剧收入分配中的＂马太效应＂,使分配不均进一步恶化,不利于形成公平、高效的初始排污权拍卖市场。     

Viability and Equilibrium in Securities Markets with Frictions

In this paper we study some foundational issues in the theory of asset pricing with market frictions. We model market frictions by letting the set of marketed contingent claims (the opportunity set) be a convex set, and the pricing rule at which these claims are available be convex. This is the reduced form of multiperiod securities price models incorporating a large class of market frictions. It is said to be viable as a model of economic equilibrium if there exist price-taking maximizing agents who are happy with their initial endowment, given the opportunity set, and hence for whom supply equals demand. This is equivalent to the existence of a positive lineaar pricing rule on the entirespace of contingent claims—an underlying frictionless linear pricing rule—that lies below the convex pricing rule on the set of marketed claims. This is also equivalent to the absence of asymptotic free lunches—a generalization of opportunities of arbitrage. When a market for a nonmarketed contingent claim opens, a bid-ask price pair for this claim is said to be consistent if it is a bid-ask price pair in at least a viable economy with this extended opportunity set. If the set of marketed contingent claims is a convex cone and the pricing rule is convex and sublinear, we show that the set of consistent prices of a claim is a closed interval and is equal (up to its boundary) to the set of its prices for all the underlying frictionless pricing rules. We also show that there exists a unique extended consistent sublinear pricing rule—the supremum of the underlying frictionless linear pricing rules—for which the original equilibrium does not collapse when a new market opens, regardless of preferences and endowments. If the opportunity set is the reduced form of a multiperiod securities market model, we study the closedness of the interval of prices of a contingent claim for the underlying frictionless pricing rules.     

在线市场的价格离散现象研究

由于信息不完全,现实市场中价格总是离散的。在线市场中,信息搜寻成本大大下降了,并且出现了可以自动搜寻各种信息包括价格信息的自动软件主体。然而实证研究表明,由于在线市场的交易行为与离线市场相比更加复杂,价格并不是消费者关注的唯一或最主要变量,因此在线市场的价格离散仍然持续存在,而且其中蕴含着更加丰富的顾客价值内涵。     

专业市场流通体系的组织结构、效率边界与演进趋势

专业市场流通体系组织结构的特点可完整地概括为两点：从组织形态来看,它是一个由集聚的中间商引领的迂回交易网络;从治理结构来看,它是基于平等商品契约的市场型治理结构。从组织形态的特点出发可以发现专业市场流通体系如何依靠集聚的中间商达成基本商品流转服务的有效率供给;从治理结构的特点出发可以了解专业市场为什么难以供给质量提升、纵向信息整合等增值服务。综合二者才能对专业市场流通体系的效率边界与演进趋势做出客观判断。然而当前对专业市场组织结构研究聚焦于考察其组织形态,忽略了对治理结构的研究。这造成对专业市场的效率边界的界定不准确,并进一步导致对其演进趋势的判断存在争议。     

多属性逆向拍卖采购机制设计

全球市场环境不断向买方市场的转变,为企业利用逆向拍卖机制进行采购创造了条件。多属性逆向拍卖机制是采购拍卖中具有广泛应用价值的机制之一,在供应商成本和采购商效用具有可加属性特征的条件下,设计了一个基于模糊评价的多属性逆向拍卖机制,将各属性等级权重值设为供应行业提供此属性等级的平均边际成本,发现该机制是激励相容的较好机制。     

中国概念股指期货跨市场套利研究——基于沪深300指数、H股指数、新华富时A50指数期货的实证分析

针对沪深300指数、H股指数、新华富时A50指数期货,给出确定投资比例、选择投资时机及度量投资风险的方法,对中国概念股指期货的跨市场套利机会进行研究,结论显示:中国沪深300股票指数与周边市场的中国概念股票指数之间存在着普遍关联性,并且这种关联性可以转化为套利机会。实证结果表明:当1:0.836546作为A50股指期货与H股股指期货的持仓比时,可以得到最优套利结果。     

基于技术效率评价的百货商业上市公司线上线下融合发展研究

通过运用DEA方法,评价分析了30家线上线下融合发展的百货商业上市公司的2020年第三季度绩效的技术效率,根据评价分析结果,将样本企业分为卓越型、良好型、规模改进型、技术改进型与成长型五种类型,并在技术效率评价的基础上提出了百货商业上市公司线上线下融合发展的重点方向.     

批发市场中电子中间商问题的分析

随着网络经济的迅速发展 ,出现了许多基于网络基础的提供信息服务的具有中介功能的电子中间商。批发市场中产品的质量存在不确定性 ,电子中间商能提高市场交易的效率 ,但物流和市场交易的分离也给市场的买卖双方带来了新的交易风险。电子中间商可以采用拍卖交易方式 ,并建立一个能降低交易风险的信用机制。信用机制的建立会促使电子市场的交易集中于高质量的产品 ,且产品的价格要高于传统市场产品价格。     

Do Arbitragers Exploit the January Effect?

The January effect has been well documented since the 1970s. This study examines whether the January effect still exists and if it does, whether arbitrageurs exploit it. We find that the January effect is still persistently significant. Furthermore, we find that arbitrageurs appear to exploit the January effect, especially in good market years when the number of losing firms is limited and are therefore more easily identifiable. We also find that the January effect tends to be higher for losing stocks with high arbitrage costs relative to those with low arbitrage costs.     

A Fundamental Theorem of Asset Pricing for Large Financial Markets

We formulate the notion of “asymptotic free lunch” which is closely related to the condition “free lunch” of Kreps (1981) and allows us to state and prove a fairly general version of the fundamental theorem of asset pricing in the context of a large financial market as introduced by Kabanov and Kramkov (1994). In a large financial market one considers a sequence (Sⁿ)_n=1^∞ of stochastic stock price processes based on a sequence (Ωⁿ, Fⁿ, (F_tⁿ)_t∈In, Pⁿ)_n=1^∞ of filtered probability spaces. Under the assumption that for all n∈ N there exists an equivalent sigma‐martingale measure for Sⁿ, we prove that there exists a bicontiguous sequence of equivalent sigma‐martingale measures if and only if there is no asymptotic free lunch (Theorem 1.1). Moreover we present an example showing that it is not possible to improve Theorem 1.1 by replacing “no asymptotic free lunch” by some weaker condition such as “no asymptotic free lunch with bounded” or “vanishing risk.”     

多层次资本市场的效率研究--以长三角多层次资本市场构建为例

资本市场效率的有效发挥与区域的经济发展水平、金融深化度、投资者理念及行为选择等特征条件密切相关,多层次资本市场是资本市场效率的重要支撑和实现途径。在此分析基础上,本文进而指出长三角地区多层次资本市场的构建和运作效率,是实现区域金融资源优化配置与资本市场制度建设的核心内容。     

Dynamics of Link Failure Events in Network Markets

We present a computational model and simulation results on the dynamics of local link failures in markets with network structure. Bandwidth markets are inherently networked, so we focus on telecommunications here. The objective of this paper is to test whether or not network failures will have serious economic consequences. We measure economic consequences by looking at changes in expected bandwidth prices, changes in value-at-risk (VAR) and in conditional-value-at-risk (CVAR). Bandwidth markets may be particularly sensitive to network failures because bandwidth is a non-storable commodity. On the other hand alternative paths with equivalent quality of service (QoS) are perfect substitutes so this may limit sensitivity. Non-storability has contributed to enormous volatility in deregulated electricity prices and observations of enormous price spikes. Bandwidth is a true network commodity in that links in the network itself are the traded commodities. Thus a local failure can affect alternative equivalent paths and this can have a knock-on effect in turn. We used a spot market model incorporating non-storability and alternative path selection on price grounds and limited by QoS-equivalence. Spike models are incorporated based on empirical data. We found that for a realistic large-scale market topology if there are, say, four failures per link per year, half of which are long enough to affect the market, then: expected link prices are increased 12%; VAR is increased by 30%; and CVAR by 40%. This is even with a spike size (×3) that is modest compared to observations in electricity markets (×10–×100). For market participants with capacity positions in such a market these consequences are likely to be serious. Thus if failures occur at this rate their consequence must be included in planning. Furthermore, whilst at low failure intensities the network acts as a dampening factor, at higher intensities it acts as an amplifier and thus cannot be neglected. We believe this amplification to be an emergent phenomenon of any market with network structure, although clearly more important for markets with no storage.     

对股票市场效率问题的四种理论分析方法

股票市场效率问题研究是金融经济学中的一个热点课题 ,很多学者对此进行了深入的研究。解释股市效率问题主要有 :有效率市场假说理论、微观信息经济学理论、行为金融学理论、以及股市内在效率和外在效率分析等四种理论分析方法。     

房地产市场有效性研究——以北京和上海为例

利用北京和上海住宅市场与写字楼市场的数据,考察了市场中收益和风险的特征,并检验了它们是否满足市场有效性的要求。统计分析结果表明,超额收益时间序列的历史值对未来的收益有一定的解释能力,同时方差比检验也表明这四个房地产市场均不具备弱有效性;租金价值比的信息可用来对未来收益进行预测,因此半强有效性的假设也能够被拒绝;在我国的房地产市场中,价格对于市场信息的反应速度比较慢,消费者往往在信息不对称的情况下进行决策,市场搜寻时间偏长,交易成本偏高。