股票分拆与并股对市场流动性的影响 --来自于香港股票市场的证据

股票分拆与并股这类事件一直迷惑着学者和实际工作者.本文利用香港股票市场的数据,研究分拆与并股对股票的市场流动性的影响.而且还研究了这类事件对股票在市场中的交易活动性的影响,以便将交易活动性与市场流动性联系起来,通过交易活动性的变化来解释造成流动性变化的根本原因.结果表明股票在分拆后流动性增强,而且是由小额交易的活跃引起的;股票在并股后流动性减弱,是由小额交易与大额交易的不活跃共同造成的.     

中国股票市场交易型的价格操纵研究

本文研究中国股票市场的交易型价格操纵问题。我们推广了Mei、Wu和Zhou(2005)的模型,研究在市场不允许卖空的条件下,交易型价格操纵发生的条件。我们的主要结果有:(1)非充分理性投资者的存在和有限套利的制约是交易型价格操纵获利的重要原因,投机者套利能力越弱,操纵者的价格操纵越容易获利;(2)当市场中投机者的总禀赋大于0时,即使不允许卖空,价格操纵者依然可以操纵价格来获得利润;(3)如果市场监管者无法杜绝操纵者通过对敲等手段来拉抬股价,则在市场中引入卖空机制反而可以减小股价对基本面的偏离程度,从而在某种程度上限制操纵者操纵股价的空间;(4)在股价被操纵的过程中,存在一个建仓期和抛盘期;操纵期内换手率更高、股价波动更大;在建仓期,回报率与换手率,换手率与回报波动率之间存在正相关关系;(5)我们利用中国股市的数据检验了我们的结论,发现理论结果和实证数据非常吻合。     

Name-Based Behavioral Biases: Are Expert Investors Immune?

The market comprises investors with a broad range of expertise. As a result, investors may make decisions differently from one another. Research reveals that investors use name-based heuristics, or short-cuts, including alphabetical ordering (Itzkowitz, Itzkowitz, and Rothbort []), name fluency (Anderson and Larkin [], Green and Jame []), and name memorability (Grullon, Kanatas, and Weston []) when trading stocks, resulting in irrational decisions. Because experts and novices process information differently, name-based biases may not affect all investors equally. The authors test and confirm the hypothesis that, compared to novices, expert investors are relatively immune to name-based biases.     

股价走势与实物经济相脱离的行为经济学分析

本文应用行为经济学的基本理论论证:与实物经济基本面因素相比,投资者损失规避行为是影响股票价格一个更为重要的因素,这在一定程度上可以解释股价走势与实物经济运行相脱离的现象.结论同时得到实证数据的支持,实证证实,与发达国家相比我国股市中投资者损失规避行为更为显著地影响股市的收益水平.本文进一步指出,在解决中国股市若干基础性问题的同时,积极输导和调控投资者行为因素也是关乎股市良性发展的一个重要问题.     

股票市场量价关系分析——模型与实证

文章将行为金融学的分析方法引入到股票市场量价关系的研究中,在考虑市场参与者非理性行为———＂急于实现盈利＂同时＂不愿结算浮亏＂的前提下,首先通过供求分析,给出股票市场中的需求曲线与供给曲线,然后设定初始均衡,采用经济学中的比较静态分析方法,研究新信息到来时对初始均衡的影响,进而分析新信息的到来对成交量和价格的影响。模型的结论是＂成交量和成交价格的变动正相关＂、＂成交量和成交价格变动的绝对值正相关＂。使用计量经济学方法,基于中国A股市场的历史数据进行了实证检验,实证结果支持了模型的结论。通过进一步分析,文章最后还得出＂投资散户是股票市场的自动稳定器＂的结论。     

The Availability Heuristic and Reversals Following Large Stock Price Changes

The author explores the effect of the availability heuristic on large daily stock price changes and on subsequent stock returns. He hypothesizes that if a major positive (negative) stock price move takes place on a day when the stock market index rises (falls), then its magnitude may be amplified by the availability of positive (negative) investment outcomes. In both cases, the availability heuristic may cause price overreaction to the initial company-specific shock, resulting in subsequent price reversal. In line with the hypothesis, the author documents that both positive and negative large price moves accompanied by the same-sign contemporaneous daily market returns are followed by significant reversals on the next 2 trading days and over 5- and 20-day intervals following the event, the magnitude of the reversals increasing over longer postevent windows, while large stock price changes taking place on the days when the market index moves in the opposite direction are followed by nonsignificant price drifts. The results remain robust after accounting for additional company (size, beta, historical volatility) and event-specific (stock's return and trading volume on the event day) factors, and are stronger for small and volatile stocks.     

Underperformance of Actively Managed Portfolios: Some Behavioral Insights

Abstract

Two glaring anomalies in investment management are apparent: (1) after fees, active portfolio managers do worse than market indices, and (2) clients continue to pay for services they don’t receive. The purpose of this paper is to offer explanations of these anomalies from a behavioral perspective. We explore some of the cognitive biases that perpetuate active management and subsequent underperformance, including herding, disposition, and endowment effects, as well as conservatism and status quo biases, overconfidence, and agency problems. Investors’ continued use of active managers despite persistent disappointing returns is attributed to being victims of framing effect, hot-hand fallacy, lack of knowledge as well as intimidation or insecurity, and status quo bias. We propose some ways that portfolio managers and investors could improve their decision making.     

股票内在投资价值理论与中国股市泡沫问题

股票内在投资价值理论是评估股票内在投资价值的依据。而只有准确评估了股票的内在投资价值,投资者和决策者才能正确认识股市泡沫问题。本文首先对股票内在投资价值理论做了综述,然后对目前最前沿的股票内在投资价值模型(基于帐面价值和剩余收益的F O模型)做了改进,使之更具有实用价值。接着利用改进后的F O模型,测算了中国股市目前的内在投资价值以及中国股市泡沫的绝对规模和相对规模。计算表明,与2 0 0 1年6月份股市高峰期相比,2 0 0 4年底中国股市泡沫的绝对规模和相对规模都已大幅度下降。文章最后提出了几点政策建议。     

关于全民炒股和股市泡沫的经济分析

近来媒体关于全民炒股特别是上班族炒股升温的报道,敲响了股市泡沫崩溃的警钟,而推动股市泡沫走向崩溃的,则是全民炒股热和上班族炒股风.中国股票市场的两大缺陷是中国股市动辄形成严重泡沫的重要原因,要彻底消除股市泡沫,必须改变股票供给严重不足和股票需求异常增大的局面,并严肃八小时工作纪律,杜绝全民炒股特别是上班炒股风.在股市钱空的程度日趋严重的形势下,对股市泡沫崩溃及其严重影响必须有清醒的认识,做好充分的准备.     

Stock options and managerial optimal contracts

Summary. In this paper we are concerned with the performance of stock option contracts in the provision of managerial incentives. In our simple framework, we restrict the space of contracts available to the principal to those conformed by a fixed payment and a call option on the firms stock. As compared to the fixed payment and the option grant, we find that the strike price plays an intermediate role in the provision of insurance and incentives. We also develop some methods for the calibration of a standard principal-agent model based upon observed CEO earnings schedules and the volatility of the firms value in the stock market. These methods are useful to address some important issues such as the performance of stock option contracts, the degree of risk aversion compatible with current earnings profiles and the sensitivity of compensation to changes in firms characteristics.Received: 9 April 2003, Revised: 13 September 2004, JEL Classification Numbers: C6, D83. Correspondence to: Manuel S. SantosWe have benefitted from helpful discussions with Marco Celentani, Hector Chade, Alejandro Manelli and Ed Schlee. We are especially grateful to an anonymous referee for very detailed comments.     

Stock market booms and real economic activity: Is this time different?

Since World War II, the United States has experienced two large booms on the stock market. During the first boom, which lasted from the late 1940s to the mid-1960s, stock returns were clearly leading real activity. Moreover, the evidence also suggests the existence of predictable return variations in the discount rate through time as a response to changing business conditions. Therefore, the first boom does not stand out as unusual because previous studies, such as Fama (1990) or Chen (1991), confirm these results for the whole period from the 1950s to the 1980s. But during the current boom, which started in the early 1980s, these results do not hold up any more. Stock returns do not seem to lead real activity and predictable return variations as a response to business conditions cannot be detected.     

非同步交易下股指期货与股票市场开收盘收益率间引导关系的实证研究

运用Granger因果检验、脉冲响应函数分析和方差分解,基于819组5分钟高频数据,对沪深300股指期货及其股票指数的开盘价格、收盘价格之间的引导关系进行检验。结果表明:期货市场与股票市场的开盘收益率相互引导;期货市场收盘收益率引导现货市场的收盘收益率和第二天开盘收益率;期货市场受自身和现货市场新息的冲击;现货市场受自身新息的冲击较大;期货市场对现货市场新息的变动更敏感;期货与现货的开盘收益率变化的总方差主要来自于现货市场,期货与现货的收盘收益率变化的总方差主要来自于期货市场。     

通货膨胀与农业股票收益多尺度分析

通货膨胀水平与股票收益率的关系是金融学研究的热点问题之一。文章介绍了小波方法的多尺度分析原理,采用农林指数月度收盘价的对数收益率和消费者价格指数分别代表农业股票收益率和通货膨胀率的水平,得到2007年9月到2012年12月农业股票收益率和通货膨胀率的统计特征。以小波方法分解已知的时间序列,得到不同尺度的数值,利用最小二乘法实证两者之间的关系,得到在中尺度和大尺度的分析周期上,两者具有统计意义上显著地正相关关系,支持了费雪效应假说。而在短尺度分析周期上,两者又具有统计意义上的负相关性,出现了费雪效应悖论。     

Serving SMEs Via the Stock Exchange: Historical Lessons from the Lisbon Stock Exchange

The development of large companies in the western world — many being huge multinational corporations — and the sheer size of their financial needs has given an added importance to tradability, a fact that can clearly be gauged by the recently discovered “high frequency trading” (HFT) operations which are only possible with large issues. Also contributing to the importance of tradability is the recent demutualization of most exchanges during the 1990s, which turned them into for-profit organizations. In fact, large issues of shares or bonds allow economies of scale, and generate experience in listing practices and trading operations, thereby enhancing the profitability of those commercially oriented stock exchanges. Thus, small and medium enterprises (SMEs) are now much less attractive to these organizations, as compared to large enterprises (LEs), due to their inherent lack of liquidity and to the economies of scale. We discuss the barriers before SMEs, which require special accommodations to be able to raise stable funds for their development.     

New Evidence on Psychology and Stock Returns

This article provides econometric evidence on the importance of psychological considerations for aggregate stock price fluctuations. To this end, a novel measure of stock market sentiment, dubbed the Net Psychology Index (NPI), based on information contained in Bloomberg News's end-of-the-day stock market reports, is confronted with a battery of multivariate empirical analyses. Results suggest that NPI is statistically different from popular sentiment proxies within the literature. NPI exhibits predictive power, increasing stock returns in the short run with this impact dissipating in the medium term. NPI does not exhibit asymmetric effects on returns for size- and momentum-related portfolios. A trading strategy based on NPI generates a statistically significant positive monthly return. Recursive out-of-sample fit analyses report a lower standard deviation of forecasting errors for NPI-based returns models versus competing accounts.     

Stock liquidity and firm value: evidence from China

Empirical evidence for the effect of stock liquidity on firm value is limited and mixed due to a severe endogeneity problem. This article adds to the literature on this topic by providing new empirical evidence using the nontradable share reform in China as a quasi-natural experiment. Our results show that higher stock liquidity can lead to significant firm value improvement.     

股价同步性与信息效率

本文通过考察股价同步性与信息效率之间的关系,澄清一个近来在金融学术和实务上有些模糊的观点,即经典的CAPM模型所决定的股价同步性,是否意味着企业信息披露更有效？通过比较信息披露指标与同步性测度的回归结果以及进一步根据同步性构造一系列组合收益发现,较低的股价同步性并不意味着更高的信息效率。事实上,较高和较低的股价同步性都意味着比较差的信息披露效率,二者呈现出“倒U”型关系。这为今后的学术研究和实务分析提供了一个新的基础。     

近期股价波动的原因及趋势分析

本文通过对最近几年股票市场现状的分析,并从经济、心理、制度、政治等因素,深层次探讨股票市场价格暴涨暴跌的原因,发现其是股票市场的一般规律和时间特征耦合在一起的结果,演绎的过程在股票市场自身性和外围众因素波动性的博弈中具有短期不可测性和长期趋势性.最后分析如何从制度上理顺股票市场,政策上应对股票市场价格剧烈波动,并对股票市场做简单长期趋势分析.     

Stock return predictability: the role of inflation and threshold dynamics

This paper argues that the nature of stock return predictability varies with the level of inflation. We contend that the nature of relations between economic variables and returns differs according to the level of inflation, due to different economic risk implications. An increase in low level inflation may signal improving economic conditions and lower expected returns, while the opposite is true with an equal rise in high level inflation. Linear estimation provides contradictory coefficient values, which we argue arises from mixing coefficient values across regimes. We test for and estimate threshold models with inflation and the term structure as the threshold variable. These models reveal a change in either the sign or magnitude of the parameter values across the regimes such that the relation between stock returns and economic variables is not constant. Measures of in-sample fit and a forecast exercise support the threshold models. They produce a higher adjusted R², lower MAE and RMSE and higher trading related measures. These results help explain the lack of consistent empirical evidence in favour of stock return predictability and should be of interest to those engaged in stock market modelling as well as trading and portfolio management.     

Behavioral Factors Affecting the Home Bias Phenomenon: Experimental Tests

Although international portfolio theory states that an optimal portfolio should be well diversified, in practice, investors tend to invest excessively in domestic assets. This tendency, which is commonly referred to in the finance literature as “home bias” (HB), has puzzled economists for many decades. This research develops and presents experiments designed to test the behavioral factors related to HB discussed in the literature. In particular, these experiments test whether the factors of “familiarity” and “fluency” (ease of pronunciation) affect HB. In addition, using a method of controlled experiments, we examine the willingness to take risk as a basic source of HB. We also examine HB under three different market conditions (normal, bear and bull markets). Results indicate that subjects tended to take less risk with foreign, unfamiliar and nonfluent (difficult to pronounce) assets compared with local, familiar and fluent assets. This tendency increased significantly when the three factors were present together (foreign, unfamiliar and nonfluent assets) compared with when only one of the three factors was present. The results also revealed that HB increased during bear market periods.