异质信念下内幕交易者市场操纵行为研究

在竞争性理性预期均衡的框架下,建立起非知情交易者异质信念下风险资产定价模型,推导出关于风险资产的贝叶斯线性均衡价格函数,并基于此研究内幕交易者市场操纵行为,揭示操纵手法。研究结果表明非知情交易者的信念偏差对交易需求、均衡价格以及内幕交易者的操纵策略均有重大影响,而对市场深度没有影响。内幕交易者通过散布虚假消息使得非知情交易者成为虚假消息的跟随者可实现获利;内幕交易者在散布虚假消息时需要考虑非知情交易者的整体信念偏差;在线性均衡下,均衡价格与内幕交易者散布的虚假消息呈线性正相关。     

指令驱动市场中非知情交易者的最优交易策略

在非对称信息下,综合非知情交易者对资产价值的预期、私人估值及资产价值波动,构造指令驱动市场价格形成的动态模型,给出非知情交易者指令提交策略的解析解,并依此描述了非知情交易者对资产价值预期的动态更新过程.研究发现:私人估值和资产价值波动通过影响非知情交易者最优策略,使得市场进入不同均衡状态;在每个均衡状态下,非知情交易者根据资产价值的预期变化更新交易策略,进而引起知情交易者策略调整,特别地,使得知情交易者被挤出市场成为可能.进一步分析表明,私人估值、资产价值波动及知情交易者比例对市场流动性的影响依赖于每个均衡中限价指令执行风险的差异.     

THE LIQUIDITY SERVICE OF BENCHMARK SECURITIES

We demonstrate that benchmark securities allow heterogeneously informed investors to create trading strategies that are perfectly aligned with their signals. Investors who are informed about security‐specific risks but uninformed about systematic risks can take an offsetting position in benchmark securities to eliminate exposure to adverse selection in systematic risks, while investors who are informed about systematic risks but uninformed about security‐specific risks can trade systematic risks exclusively using benchmark securities. We further show that introduction of benchmark securities encourages more investors to acquire both security‐specific and systematic‐factor information, which leads to increased liquidity and price informativeness for all individual securities. (JEL: G10, G12, G14)     

Impact of Reseller's Forecasting Accuracy on Channel Member Performance

This article studies a three‐layer supply chain where a manufacturer sells a product through a reseller who then relies on its own salesperson to sell to the end market. The reseller has superior capability in demand forecasting relative to the manufacturer. We explore the main trade‐offs between the risk‐reduction effect and the information–asymmetry–aggravation effect of the improved forecasting accuracy. We show that under the optimal wholesale price contract, both the manufacturer and the reseller are always better off as the reseller's forecasting accuracy improves. Nevertheless, under the menu of two‐part tariffs, the manufacturer prefers the reseller to be either uninformed or perfectly informed about the market condition. We further find that the improved forecasting accuracy is beneficial for the reseller if its current forecasting system is either very poor or very good.     

Insider Trading,Stochastic Liquidity,and Equilibrium Prices

We extend Kyle's (1985) model of insider trading to the case where noise trading volatility follows a general stochastic process. We determine conditions under which, in equilibrium, price impact and price volatility are both stochastic, driven by shocks to uninformed volume even though the fundamental value is constant. The volatility of price volatility appears ‘excessive’ because insiders choose to trade more aggressively (and thus more information is revealed) when uninformed volume is higher and price impact is lower. This generates a positive relation between price volatility and trading volume, giving rise to an endogenous subordinate stochastic process for prices.     

Waiting for News in the Market for Lemons

We study a dynamic setting in which stochastic information (news) about the value of a privately informed seller's asset is gradually revealed to a market of buyers. We construct an equilibrium that involves periods of no trade or market failure. The no‐trade period ends in one of two ways: either enough good news arrives, restoring confidence and markets reopen, or bad news arrives, making buyers more pessimistic and forcing capitulation that is, a partial sell‐off of low‐value assets. Conditions under which the equilibrium is unique are provided. We analyze welfare and efficiency as they depend on the quality of the news. Higher quality news can lead to more inefficient outcomes. Our model encompasses settings with or without a standard static adverse selection problem—in a dynamic setting with sufficiently informative news, reservation values arise endogenously from the option to sell in the future and the two environments have the same equilibrium structure.     

SECESSIONS AND POLITICAL EXTREMISM: WHY REGIONAL REFERENDA DO NOT SOLVE THE PROBLEM

This paper shows that an uninformed player can increase his bargaining power by committing to receive information from an expert more skeptical to cooperation. This general idea is applied to a model in which a regional political leader (the expert) influences voting in a referendum on independence by strategically disseminating information about the consequences of separation. I show that this motivates a moderate electorate to appoint a more extreme leader, to receive biased information that increases their bargaining power over the gains of staying unified. However, a trade‐off between bargaining power and precision of information causes inefficient outcomes in equilibrium. (JEL: C73, D72, D82, H77)     

询价制度改革、知情交易者概率与IPO溢价

O'Hara理性预期模型假设非知情交易者对市场交易价格信息存在完全学习行为,从而知情交易者概率对资产期望收益产生负向效应。本文放松这一假设,引入非知情交易者学习程度,在理性预期模型框架下,以新股发行市场为背景对理性预期模型进行了拓展,模型结论表明：非知情交易者对市场交易价格的学习行为影响了知情交易者概率与资产期望收益的关系;当市场非知情交易者存在学习行为时,随着非知情交易者的学习程度加深,知情交易者概率对资产期望收益产生负向影响。在进一步的实证研究中,通过羊群效应验证了市场上非知情交易者的学习行为,以2010年1月到2011年12月在中小板上市的278家IPO公司为样本,对模型进行实证检验,实证结果支持理论模型结论。本研究对已有实证研究中知情交易者概率对资产收益产生正或负效应这一矛盾的研究结论提出了一种理论解释,并基于此对询价制度改革的有效性进行了检验。本文研究结论对知情交易者概率在资产定价中的适用性具有一定启示性,同时对非知情交易者的学习行为提出了一种实证检验的方法,具有一定的开创性。     

Options Contracts with Overbooking in the Air Cargo Industry

In today's world economy, which is marked by intensified international trade, air cargo acts as a key facilitator. However, cargo airlines continue to struggle to be profitable because of very high asset costs and substantial demand uncertainty. To improve upon this situation, we propose an options contract. Our model captures the main features of cargo trade between an airline and a freight forwarder and allows us to derive an optimal reservation policy. We then go on to analyze the impact of overbooking on the profit of the cargo capacity provider. The model is subsequently applied to real‐life booking data provided by a major cargo carrier. This enables us to compare current contractual arrangements with the ones proven optimal in the model. A numerical study provides insights about the impact of overbooking on contract parameters and profitability. Managerial insights to be drawn conclude this study.     

A Robust Model of Bubbles With Multidimensional Uncertainty

Observers often interpret boom–bust episodes in asset markets as speculative frenzies where asymmetrically informed investors buy overvalued assets hoping to sell to a greater fool before the crash. Despite its intuitive appeal, however, this notion of speculative bubbles has proven difficult to reconcile with economic theory. Existing models have been criticized on the basis that they assume irrationality, that prices are somewhat unresponsive to sales, or that they depend on fragile, knife‐edge restrictions. To address these issues, I construct a rational version of Abreu and Brunnermeier (2003), where agents invest growing endowments into an asset, fueling appreciation and eventual overvaluation. Riding bubbles is optimal as long as the growth rate of the bubble and the probability of selling before the crash are high enough. This probability increases with the amount of noise in the economy, as random short‐term fluctuations make it difficult for agents to infer information from prices.     

PUBLIC DEBT UNDER LIMITED PRIVATE CREDIT

There is a conventional wisdom in economics that public debt can serve as a substitute for private credit if private borrowing is limited. The purpose of this paper is to show that, while a government could in principle use such a policy to fully relax borrowing limits, this is not generally optimal. In our economy, agents invest in a short‐term asset, a long‐term asset, and government bonds. Agents are subject to idiosyncratic liquidity shocks prior to the maturity of the long‐term asset. We show that a high public debt policy fully relaxes private borrowing limits and is suboptimal. This is because agents expecting such a policy respond by investing less than is socially optimal in the short asset which can protect them in the event of a liquidity shock. The optimal policy is more constrained and it induces a wedge between the technological rate of return on the long asset and the rate of return on bonds. In such a regime, agents subject to liquidity shocks are also borrowing constrained, and this expectation of being borrowing constrained induces them to invest the optimal level in the short asset.     

Cursed Equilibrium

There is evidence that people do not fully take into account how other people's actions depend on these other people's information. This paper defines and applies a new equilibrium concept in games with private information, cursed equilibrium, which assumes that each player correctly predicts the distribution of other players' actions, but underestimates the degree to which these actions are correlated with other players' information. We apply the concept to common‐values auctions, where cursed equilibrium captures the widely observed phenomenon of the winner's curse, and to bilateral trade, where cursedness predicts trade in adverse‐selections settings for which conventional analysis predicts no trade. We also apply cursed equilibrium to voting and signalling models. We test a single‐parameter variant of our model that embeds Bayesian Nash equilibrium as a special case and find that parameter values that correspond to cursedness fit a broad range of experimental datasets better than the parameter value that corresponds to Bayesian Nash equilibrium.     

Asset Markets With Heterogeneous Information

This paper studies competitive equilibria of economies where assets are heterogeneous and traders have heterogeneous information about them. Markets are defined by a price and a procedure for clearing trades, and any asset can, in principle, be traded in any market. Buyers can use their information to impose acceptance rules which specify which assets they are willing to trade in each market. The set of markets where trade takes place is derived endogenously. The model can be applied to find conditions under which these economies feature fire sales, contagion, and flights to quality.     

Over‐the‐Counter Markets

We study how intermediation and asset prices in over‐the‐counter markets are affected by illiquidity associated with search and bargaining. We compute explicitly the prices at which investors trade with each other, as well as marketmakers' bid and ask prices, in a dynamic model with strategic agents. Bid–ask spreads are lower if investors can more easily find other investors or have easier access to multiple marketmakers. With a monopolistic marketmaker, bid–ask spreads are higher if investors have easier access to the marketmaker. We characterize endogenous search and welfare, and discuss empirical implications.     

长期资产减值信息有用性的实证检验——来自银行借款契约角度

本文实证检验了长期资产减值信息在企业与银行借款契约中的作用.研究发现,长期资产减值反映了企业未来盈利的预期,长期资产减值越多的企业未来业绩越差;长期资产减值信息为银行所接受,长期资产减值越参的企业获得的银行借款总量越少;且银行更倾向用短期借款代替长期借款,以降低风险;所有权性质、地区性质对长期资产减值信息的有用性存在影响,民营企业、东部地区企业长期资产减值信息的有用性更强;借款契约期限的差异、减值信息质量的差异也会影响长期资产减值信息的有用性.     

Information in Securities Markets: Kyle Meets Glosten and Milgrom

This paper analyzes models of securities markets with a single strategic informed trader and competitive market makers. In one version, uninformed trades arrive as a Brownian motion and market makers see only the order imbalance, as in Kyle (1985). In the other version, uninformed trades arrive as a Poisson process and market makers see individual trades. This is similar to the Glosten–Milgrom (1985) model, except that we allow the informed trader to optimize his times of trading. We show there is an equilibrium in the Glosten–Milgrom‐type model in which the informed trader plays a mixed strategy (a point process with stochastic intensity). In this equilibrium, informed and uninformed trades arrive probabilistically, as Glosten and Milgrom assume. We study a sequence of such markets in which uninformed trades become smaller and arrive more frequently, approximating a Brownian motion. We show that the equilibria of the Glosten–Milgrom model converge to the equilibrium of the Kyle model.     

Communicating Asset Risk: How Name Recognition and the Format of Historic Volatility Information Affect Risk Perception and Investment Decisions

An experiment examined how the type and presentation format of information about investment options affected investors' expectations about asset risk, returns, and volatility and how these expectations related to asset choice. Respondents were provided with the names of 16 domestic and foreign investment options, with 10-year historical return information for these options, or with both. Historical returns were presented either as a bar graph of returns per year or as a continuous density distribution. Provision of asset names allowed for the investigation of the mechanisms underlying the home bias in investment choice and other asset familiarity effects. Respondents provided their expectations of future returns, volatility, and expected risk, and indicated the options they would choose to invest in. Expected returns closely resembled historical expected values. Risk and volatility perceptions both varied significantly as a function of the type and format of information, but in different ways. Expected returns and perceived risk, not predicted volatility, predicted portfolio decisions.     

羊群效应与内幕信息的揭示分析

本文用金融市场微观结构模型的序贯交易框架分析了证券市场上的多维不确定性怎样引起投资者的羊群交易行为。结论表明当市场上存在事件不确定和信息精度不确定时,投资者之间可能发生羊群行为,这种行为会导致内幕信息在一段时间内得不到有效揭示。做市商在发生羊群效应期间虽然只能判断出事件的存在性,而无法学习到内幕信息的好坏和精度,但他仍会继续调整资产的价格并最终结束羊群效应。     

Speculative Overpricing in Asset Markets With Information Flows

In this paper, we derive and experimentally test a theoretical model of speculation in multiperiod asset markets with public information flows. The speculation arises from the traders' heterogeneous posteriors as they make different inferences from sequences of public information. This leads to overpricing in the sense that price exceeds the most optimistic belief about the real value of the asset. We find evidence of speculative overpricing in both incomplete and complete markets, where the information flow is a gradually revealed sequence of imperfect public signals about the state of the world. We also find evidence of asymmetric price reaction to good news and bad news, another feature of equilibrium price dynamics under our model. Markets with a relaxed short‐sale constraint exhibit less overpricing.     

An Elementary Theory of Comparative Advantage

Comparative advantage, whether driven by technology or factor endowment, is at the core of neoclassical trade theory. Using tools from the mathematics of complementarity, this paper offers a simple yet unifying perspective on the fundamental forces that shape comparative advantage. The main results characterize sufficient conditions on factor productivity and factor supply to predict patterns of international specialization in a multifactor generalization of the Ricardian model which we refer to as an “elementary neoclassical economy.” These conditions, which hold for an arbitrarily large number of countries, goods, and factors, generalize and extend many results from the previous trade literature. They also offer new insights about the joint effects of technology and factor endowments on international specialization.