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.     

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.     

基于理性预期均衡框架下的价格泡沫与过度反应研究

基于理性预期均衡框架,分别在私人信息外生和内生获取的条件下研究知情交易者对新信息过度反应与价格泡沫之间的联系。研究发现：在私人信息外生获取的情况下,知情交易者对新信息过度反应会提高价格信息量。在私人信息内生获取的情况下,过度反应挤出了私人信息的生产,导致价格信息量降低,价格泡沫由此形成,此时流动性可能呈先降低后提高的U型变化。这为管理层加强私人信息披露和弱化投资者的过度反应程度提供了依据。     

MEDIA MERGERS AND MEDIA BIAS WITH RATIONAL CONSUMERS

We present an economic model of media bias and media mergers. Media owners have political motives as well as profit motives, and can influence public opinion by withholding information that is pejorative to their political agenda—provided that their agenda is not too far from the political mainstream. This is true even with rational consumers who understand the media owners’ biases, because the public do not know how much information the news organizations have and so do not know when news is being withheld. In line with conventional wisdom, this problem can be undone by competition; but competition can be defeated in equilibrium by media mergers that enhance profits at the expense of the public interest. We thus derive a motive for media merger policy that is completely distinct from the motives behind conventional antitrust. While media bias may reduce the profit incentives to merge, media markets nonetheless err by being insufficiently competitive, and the consequences of merger are more severe than in other markets.     

机构投资者私人信息、散户投资者情绪与IPO首日回报率

针对影响IPO首日回报率的一级市场与二级市场因素,本文将机构投资者的私人信息和散户投资者的情绪结合起来,以我国新股发行市场为背景建立模型,对IPO破发或抑价产生的微观机制给出一种理论上的解释。模型结论表明:IPO是否破发主要取决于散户投资者的情绪,而不是机构投资者的私人信息,并且散户投资者情绪越乐观,IPO破发的可能性就越小;同时发现IPO首日回报率与散户投资者情绪正相关,与机构投资者的私人信息负相关。以2010年11月至2013年12月在沪深交易所上市且披露网下具体报价情况的477家IPO公司为样本对模型进行实证检验,实证结果支持了模型结论。研究结果对于如何提高IPO发行效率提供了一些启示。     

基于注意力传染机制的股市动量与反转模型研究

针对我国股市参与程度低,投资者非理性以及股价暴涨暴跌的基本事实,本文在一个简单的定价模型中刻画了新投资者参与市场背后的注意力传染机制,发现投资者关注在资产价格形成过程中扮演双重角色:一方面投资者的有限关注导致价格对信息反应不足,引起收益动量;另一方面,关注投资者通过注意力传染机制诱导无经验的正反馈交易者进入市场,导致收益反转。因此,注意力传染机制的引入合理地解释了股票动量效应与反转效应并存的事实,对于理解在成熟市场与新兴市场中投资者关注定价效应的差异具有重要意义。     

跳跃、共跳和非预期宏观信息

文章基于5 min高频数据研究了股票市场和债券市场资产价格的高频跳跃和共跳以及它们与定期发布的宏观经济信息的关系.结果表明,股票市场和债券市场具有显著的跳跃性和共跳性,债券市场跳跃的概率远高于股票市场,而股票市场的跳跃幅度远高于债券市场.非预期宏观经济信息不仅显著地影响股票市场和债券市场的跳跃幅度,还影响两个市场的共跳.定期发布的国内生产总值、固定资产投资、居民消费价格指数、采购经理指数、工业品出厂价格指数、贸易差额和工业增加值等指标显著地影响股市债市的共跳.     

Nonspeculative Bubbles in Experimental Asset Markets: Lack of Common Knowledge of Rationality vs. Actual Irrationality

We report the results of an experiment designed to study the role of speculation in the formation of bubbles and crashes in laboratory asset markets. In a setting in which speculation is not possible, bubbles and crashes are observed. The results suggest that the departures from fundamental values are not caused by the lack of common knowledge of rationality leading to speculation, but rather by behavior that itself exhibits elements of irrationality. Much of the trading activity that accompanies bubble formation, in markets where speculation is possible, is due to the fact that there is no other activity available for participants in the experiment.     

The Economic Value of Market Information for Farmers in Developing Economies

In developing countries, farmers lack information for making informed production, manufacturing/selling decisions to improve their earnings. To alleviate poverty, various non‐governmental organizations (NGOs) and for‐profit companies have developed different ways to distribute information about market price, crop advisory and farming technique to farmers. We investigate a fundamental question: will information create economic value for farmers? We construct a stylized model in which farmers face an uncertain market price (demand) and must make production decisions before the market price is realized. Each farmer has an imprecise private signal and an imprecise public signal to estimate the actual market price. By examining the equilibrium outcomes associated with a Cournot competition game, we show that private signals do create value by improving farmers' welfare. However, this value deteriorates as the public signal becomes available (or more precise). In contrast, in the presence of private signals, the public signal does not always create value for the farmers. Nevertheless, both private and public signals will reduce price variation. We also consider two separate extensions that involve non‐identical private signal precisions and farmers' risk‐aversion, and we find that the same results continue to hold. More importantly, we find that the public signal can reduce welfare inequality when farmers have non‐identical private signal precisions. Also, risk‐aversion can dampen the value created by private or public information.     

UNINSURED COUNTERCYCLICAL RISK: AN AGGREGATION RESULT AND APPLICATION TO OPTIMAL MONETARY POLICY

We consider an incomplete markets economy with capital accumulation and endogenous labor supply. Individuals face countercyclical idiosyncratic labor and asset risk. We derive conditions under which the aggregate allocations and price system can be found by solving a representative agent problem. This result is applied to analyze the properties of an optimal monetary policy in a New Keynesian economy with uninsured countercyclical individual risk. The optimal monetary policy that emerges from our incomplete markets economy is the same as the optimal monetary policy in a representative agent model with preference shocks. When price rigidity is the only friction the optimal monetary policy calls for stabilizing the inflation rate at zero.     

交叉上市股票价格发现能力差异及交易信息含量测度

本文在市场微观结构的理论框架下,对交叉上市股票的价格发现过程进行了分析。在Hasbrouck信息分成技术的基础上,提供了一种新的方法使其能够对市场交易过程中的公开信息和私有信息含量进行分解和测度。研究过程以 "A+H"交叉上市股票为研究对象,对本文的模型和方法进行了具体的应用和验证。     

非完全市场条件下的0-水平资产定价法研究

资产的0-水平定价法是指投资者在特定的效用函数和财富水平状况下已取得的最优投资组合,不会因新的资产出现及其相应的定价而调整,即对新资产的定价使追求效用最大化的投资者对新资产的最佳持有量为零。因此对新资产采用0-水平定价不会使市场产生套利机会。本文主要介绍Lenberger等人提出的0-水平定价的概念、方法及性质,并且将这种定价方法与e-套利定价方法进行比较,然后证明了在局部完全市场里,0-水平定价与e-套利定价的一致性。     

中国股票价格跳跃实证研究

利用基于BN -S方法的已实现波动测度构造出跳跃统计量,用该统计量检验分析了中国股票市场股票价格的跳跃现象.检验结果不仅证实了股票市场价格跳跃存在普遍性,而且发现单支股票的跳跃主要是异质跳跃而不是共同跳跃.这表明单支股票的价格跳跃更多地受到自身市场信息的影响,而共同信息对单支股票的影响是非常有限的.单支股票的共同跳跃大...     

证券市场价格行为系统动力学研究

区分了证券市场上基于基本面因素和基于股价变动交易的两类投资者,建立了证券市场的系统动力学模型,刻画了证券市场的基本结构和内部信息反馈机制,模拟和分析了基于基本面因素交易的投资者信息差异程度、公共信息、投资者流动性需求、心理特点以及两类投资者的相对比例对价格及成交量行为的影响.     

不确定环境下的期权价格上下界研究

传统的期权定价理论总是建立在标的资产价格分布的严格假设下,而没有考虑分布的不确定性。本文对标的资产价格分布的严格假设进行放松,分别在仅知到期日标的资产价格的前二阶矩及前三阶矩,而不知道其具体分布的条件下,对期权进行定价。由于信息不充分及分布不确定,推导出的期权价格为一个区间。我们针对有限信息条件下求解期权价格上下界的问题,建立数学规划模型,并将其转化为对偶规划问题进行求解。对此上下界和Black-Scholes价格进行对比分析后发现,Black-Scholes价格介于此上下界之间,相对于采用前二阶矩推导的上下界,采用前三阶矩信息推导的上下界更窄。在使用香港恒生指数权证数据进行的时序分析及横截面分析中发现,市场价格确实介于上下界之间,上下界区间随波动率及剩余存续期的减小而缩小。采用本文的定价方法,不需要对资产价格分布进行严格假设,故可提高定价模型的稳健性,有助于投资者结合期权价格上下界及自己的主观判断进行投资决策。     

Understanding Mechanisms Underlying Peer Effects: Evidence From a Field Experiment on Financial Decisions

Using a high‐stakes field experiment conducted with a financial brokerage, we implement a novel design to separately identify two channels of social influence in financial decisions, both widely studied theoretically. When someone purchases an asset, his peers may also want to purchase it, both because they learn from his choice (“social learning”) and because his possession of the asset directly affects others' utility of owning the same asset (“social utility”). We randomize whether one member of a peer pair who chose to purchase an asset has that choice implemented, thus randomizing his ability to possess the asset. Then, we randomize whether the second member of the pair: (i) receives no information about the first member, or (ii) is informed of the first member's desire to purchase the asset and the result of the randomization that determined possession. This allows us to estimate the effects of learning plus possession, and learning alone, relative to a (no information) control group. We find that both social learning and social utility channels have statistically and economically significant effects on investment decisions. Evidence from a follow‐up survey reveals that social learning effects are greatest when the first (second) investor is financially sophisticated (financially unsophisticated); investors report updating their beliefs about asset quality after learning about their peer's revealed preference; and, they report motivations consistent with “keeping up with the Joneses” when learning about their peer's possession of the asset. These results can help shed light on the mechanisms underlying herding behavior in financial markets and peer effects in consumption and investment decisions.     

内部控制信息披露与市场反应研究——来自中国沪市上市公司的经验证据

本文以2006-2009年沪市A股上市公司为研究对象,实证考察了内部控制信息披露的市场反应。研究发现,从总体上看,我国上市公司内部控制信息披露具有明显的市场反应,但从不同侧面看,内部控制信息披露的市场反应存在显著差异:从披露内容看,内部控制有效引起股票价格上涨,而内部控制缺陷则引起股票价格下跌;从披露类型看,强制性披露较自愿性披露更具有价值相关性;从披露详略看,详细披露会引起股票价格上涨,而简单披露则不一定。此外,与单独的强制性披露或自愿性披露的市场反应相比,内部控制强制性披露和自愿性披露交互影响的市场反应更加显著。据此本文认为,在进一步加强强制性披露的日常监管的同时完善自愿性披露的激励政策,是当前规范我国上市公司内部控制信息披露行为和提高内部控制信息披露质量的关键。     

SEPARATING MORAL HAZARD FROM ADVERSE SELECTION AND LEARNING IN AUTOMOBILE INSURANCE: LONGITUDINAL EVIDENCE FROM FRANCE

The identification of information problems in different markets is a challenging issue in the economic literature. In this paper, we study the identification of moral hazard from adverse selection and learning about risk within the context of a multi‐period dynamic model. We extend the model of Abbring, Chiappori, and Pinquet (2003, Journal of the European Economic Association, 1, 767–820) to include learning about risk and insurance coverage choice over time. We derive testable empirical implications for panel data. We then perform tests using longitudinal data from France during the period 1995–1997. We find evidence of moral hazard among a sub‐group of policyholders with less driving experience (less than 15 years). Policyholders with fewer than five years of experience have a combination of learning about risk and moral hazard, whereas no residual information problem is found for policyholders with more than 15 years of experience.     

投资者结构、交易失衡与商品期货市场的价格发现效率

基于上海期货交易所铝、铜、橡胶和燃料油期货合约两种投资者结构的分账户数据,分析不同类型投资者交易失衡对我国商品期货市场收益、价格发现与波动的影响。结果表明:(1)个人投资者和投机者的交易失衡暗示其寻找最佳买多或卖空时点的能力不足,存在明显的过度自信、过度投机和羊群行为,加剧商品期货价格波动;(2)机构投资者和套期保值者常常表现出与个人投资者和投机者相反的交易意愿,他们能够较好地把握买入与卖出时机,且更愿意冒险持有头寸,有助于缓解商品期货价格波动;(3)商品期货价格的变动趋势表明机构投资者和套期保值者具有一定的信息优势,能够在一定程度上预测商品期货价格的未来走势,他们极其乐观或悲观的交易失衡可以向商品期货市场传递有效的信息和时间信号。因此,提高机构投资者和套期保值者的成交量(持仓量)比例,优化投资者结构,可以有效促进我国商品期货市场的价格发现,降低期货价波动风险。此外,大型投机者的交易活动也可以在一定程度上缓解商品期货价格波动。     

The Bubble Game: An Experimental Study of Speculation

We propose a bubble game that involves sequential trading of an asset commonly known to be valueless. Because no trader is ever sure to be last in the market sequence, the game allows for a bubble at the Nash equilibrium when there is no cap on the maximum price. We run experiments both with and without a price cap. Structural estimation of behavioral game theory models suggests that quantal responses and analogy‐based expectations are important drivers of speculation.