ADAPTIVE EXPECTATIONS AND STOCK MARKET CRASHES*

A theory is developed that explains how stocks can crash without fundamental news and why crashes are more common than frenzies. A crash occurs via the interaction of rational and naive investors. Naive traders believe that prices follow a random walk with serially correlated volatility. Their expectations of future volatility are formed adaptively. When the market crashes, naive traders sell stock in response to the apparent increase in volatility. Since rational traders are risk averse as well, a lower price is needed to clear the market: The crash is a self‐fulfilling prophecy. Frenzies cannot occur in this model.     

互联网沟通与股价崩盘风险

本文采用2010年第1季度—2015年第3季度深交所上市公司作为研究对象,对“互动易”问答平台上企业与投资者沟通的内容与股价崩盘风险之间的关系进行了研究,具体而言,研究投资者提问以及董秘回复的负面语气是否能够降低相应公司股价崩盘风险。研究发现：首先,投资者提问的负面语气能够显著降低公司的股价崩盘风险,董秘回复的负面语气则与股价崩盘风险不相关。其次,机构投资者持股比例较高或持股户数较多的股票,公司股价崩盘风险与投资者提问的负面语气之间的负向关系更强。此外,进一步的分析表明,投资者提问的语气越负面,机构投资者下期的持仓越小,越倾向于卖出股票,且投资者提问的负面语气能够显著地降低信息不对称;投资者正面语气与股价崩盘风险之间不存在显著的相关性。本文为管理层与投资者信息交流机制方面的研究以及股价崩盘风险方面的文献提供了有益的补充。     

非流通股对股票市场和上市公司的影响

本文构造了一个股票市场均衡模型来分析非流通股的存在对中国股票市场和上市公司的影响。我们发现非流通股的存在,使得股票市场价格发现机制扭曲,一方面使得股票价格不能真实地反映上市公司的经营绩效,另一方面使得流通股市场的股价波动与流通股比例密切相关。而且从我们的实证分析证实,非流通股比例越高,流通股市场的股价波动就越大,股票价格中含有的非流通股的放大作用越大,非流通股的存在也会影响经理人员的激励和报酬水平。     

高送转与股价崩盘风险:抑制还是加重

本文以我国2003—2015年A股公司为样本,考察了公司“高送转”与股价崩盘风险之间的关系。研究发现,公司“高送转”能够有效抑制股价崩盘风险,相对于创业板,主板公司“高送转”抑制股价崩盘风险的作用更为显著。而且,“高送转”对于股价崩盘风险的抑制作用并不受公司财务状况和减持情况的影响,该抑制作用的期限超过了我国投资者平均持股时间。本文有助于加深人们对于“高送转”经济后果的认识。     

CEO过度自信、权力配置与股价崩盘风险*

基于沪深两市2006—2013年A股上市公司的面板数据,本文从行为金融视角出发考察了CEO过度自信心理特征及其权力配置对股价崩盘风险的影响。研究发现CEO过度自信会增大公司股价崩盘风险;并且,随着CEO权力增大,过度自信更容易导致公司股价崩盘现象发生。进一步将CEO权力细分为选择权和决断权之后发现,只有CEO决断权增大能显著加剧过度自信对股价崩盘风险的负面影响,且这一关系只有在选择权得到保证后成立。     

投资者情绪、市场波动与股市泡沫

我国投资者情绪容易受到噪音交易者影响,其他类型交易者可利用噪音交易者的交易策略在博弈中获取超额利润,这为投机性泡沫的产生提供了微观基础。在市场波动机制中,投资者情绪与股价变化存在动态关系,股价泡沫存在内在持续性,引发市场正反馈效应,从而促成投机性泡沫的生成。     

股市发展与收入分配不平等

股市发展与收入分配状况的关系是金融理论界和业界广泛关注的问题之一。本文构造全球33个国家从1988年至2013年有关股市发展和收入分配不平等的面板数据,实证研究各国股市发展及自由化改革对其收入分配不平等程度的影响及内在机理。研究发现：首先,一国股市规模越大,由于门槛效应的存在,其收入分配状况趋于恶化,而流动性的提升将在一定程度上改善其收入分配状况。其次,一国股市的发展对不同收入阶层存在不同的影响。最后,股市自由化前后,股市对收入分配状况的影响存在显著差异：股市自由化之后,股市规模的扩大和股市流动性的提升将在一定程度上改善收入分配状况。     

中国股市与世界其他股市之间的大风险溢出效应

该文分析了中国证券市场A股、B股和H股之间,中国股市与世界其他股票市场之间的极端风险的溢出效应.实证结果表明:A股与B股之间存在着强烈的风险溢出效应,B股大幅下跌的信息可用来预测未来A股大幅下跌的可能性;A股和H股之间,尤其是B股和H股之间也存在着强烈的风险溢出效应;B股,尤其是H股,与世界其他股市之间存在着显著的风险溢出效应;与此相反,A股虽然与韩国、新加坡股市之间存在着一定的风险溢出效应,但它与日本、美国和德国等世界主要股市之间不存在任何风险溢出效应.     

我国上市公司资产重组的行业分析

本文首先从工业行业运行状况的角度,定量化地研究了我国资本市场中兼并频发行业的成因。研究发现,工业行业的集中度偏低是其中最主要的原因。本文还以各个兼并频发行业内发生资产重组的上市公司为研究对象,发现我国不同的行业,资本市场中资产重组的方式有所不同。同时资本市场中行业资产的重组对于不同行业的产业结构调整有着不同的积极或消极的作用。这表明我国资本市场上的资产重组将导致我国工业各行业的竞争力呈分化状态。     

EFFICIENCY OF THE TAIWAN STOCK MARKET*

This study uses two popular technical trading rules to assess whether the gradual liberalization of Taiwan's securities markets has improved the efficiency of its stock market. The results show that the two rules have considerable predictive power for 1983–1990, they become less predictive for 1991–1997, and they cannot predict the market for 1998–2005. These results indicate that the efficiency of Taiwan stock market has been greatly enhanced by the liberalization measures implemented over the last 20 years.     

PARTISAN POLITICS, INTEREST RATES AND THE STOCK MARKET: EVIDENCE FROM AMERICAN AND BRITISH RETURNS IN THE TWENTIETH CENTURY

We examine the relationship between government partisanship, interest rates and the mean and volatility of stock prices in the United States and United Kingdom. We suggest that traders in the stock market rationally expect higher (lower) post-electoral interest rates during the incumbency of the left-wing (right-wing) party – Democrats and Labor (Republican and Conservative) – and in election years when they expect the left-wing (right-wing) party to win elections. We hypothesize that expectations of higher (lower) interest rates decrease (increase) the mean and volatility of stock prices during the actual incumbency or even anticipation of a left-wing (right-wing) party holding the office of the chief executive. Results from empirical models estimated on data from U.S. and U.K. markets over most of the twentieth century statistically support our claims.     

FINANCIAL CRISES AND INTERNATIONAL STOCK MARKET VOLATILITY TRANSMISSION

This paper examines the interplay between stock market returns and their volatility, focusing on the Asian and global financial crises of 1997–98 and 2008–09 for Australia, Singapore, the UK, and the US. We use a multivariate generalised autoregressive conditional heteroskedasticity (MGARCH) model and weekly data (January 1992–June 2009). Based on the results obtained from the mean return equations, we could not find any significant impact on returns arising from the Asian crisis and more recent global financial crises across these four markets. However, both crises significantly increased the stock return volatilities across all of the four markets. Not surprisingly, it is also found that the US stock market is the most crucial market impacting on the volatilities of smaller economies such as Australia. Our results provide evidence of own and cross ARCH and GARCH effects among all four markets, suggesting the existence of significant volatility and cross volatility spillovers across all four markets. A high degree of time‐varying co‐volatility among these markets indicates that investors will be highly unlikely to benefit from diversifying their financial portfolio by acquiring stocks within these four countries only.     

实验市场中的价格预期

采用4个变化的口头双向拍卖模拟市场(2个先稳定后通胀,2个先通胀后稳定),本研究发现通胀市场中的预期与理性预期假设吻合良好,同时通货预期不受通胀率的影响。相反稳定市场不支持理性预期模型。结合Williams(1987)的研究结果,本研究提示市场设置是影响稳定市场和通胀市场表现差异的主要原因。     

实验市场中的价格预期

采用4个变化的口头双向拍卖模拟市场(2个先稳定后通胀,2个先通胀后稳定),本研究发现通胀市场中的预期与理性预期假设吻合良好,同时通货预期不受通胀率的影响.相反稳定市场不支持理性预期模型.结合Williams(1987)的研究结果,本研究提示市场设置是影响稳定市场和通胀市场表现差异的主要原因.     

SECULAR MEAN REVERSION AND LONG‐RUN PREDICTABILITY OF THE STOCK MARKET

The empirical financial literature reports evidence of mean reversion in stock prices and the absence of out‐of‐sample return predictability over horizons shorter than 10 years. Anecdotal evidence suggests the presence of mean reversion in stock prices and return predictability over horizons longer than 10 years, but thus far, there is no empirical evidence confirming such anecdotal evidence. The goal of this paper is to fill this gap in the literature. Specifically, using 141 years of data, this paper begins by performing formal tests of the random walk hypothesis in the prices of the real S&P Composite Index over increasing time horizons of up to 40 years. Although our results cannot support the conventional wisdom that the stock market is safer for long‐term investors, our findings speak in favor of the mean reversion hypothesis. In particular, we find statistically significant in‐sample evidence that past 15‐17 year returns are able to predict the future 15‐17 year returns. This finding is robust to the choice of data source, deflator, and test statistic. The paper continues by investigating the out‐of‐sample performance of long‐horizon return forecasting based on the mean‐reverting model. These latter tests demonstrate that the forecast accuracy provided by the mean‐reverting model is statistically significantly better than the forecast accuracy provided by the naive historical‐mean model. Moreover, we show that the predictive ability of the mean‐reverting model is economically significant and translates into substantial performance gains.     

中国股票市场:2004年回顾与2005年展望

累积多年的股市矛盾和问题在2004年集中显露出来,导致危局凸现。2005年的股市走势取决于股票发行规模、资金供给状况、上市公司质量改进、市场监管、股票全流通等因素,存在着较大的不确定性。     

年轻高管与企业股价崩盘风险：来自“代理冲突观”的证据*

在企业纷纷实施高管年轻化战略的背景下，本文从股价崩盘风险的视角分析和检验了年轻高管风险偏好的经济后果及其作用机理。本文基于“个体认知观”和“代理冲突观”展开理论推演，采用中国沪深A股非金融上市公司的数据，检验发现，年轻高管会显著加剧企业未来的股价崩盘风险，且这种影响主要存在于民营企业，在国有企业并不显著。进一步针对具体作用机制的检验发现，年轻高管在投资决策中选择了更多能迅速提升个人收益的风险性投资项目，但在不能迅速提升个人收益的风险性投资项目上与年长高管没有显著差异。同时，年轻高管对股价崩盘风险的加剧效应仅仅存在于高管在上市公司领取薪酬的样本企业，且更高的独立董事比例能显著抑制年轻高管的股价崩盘风险加剧效应。这表明，年轻高管个体认知层面的风险偏好被其追求个人私利最大化的代理冲突所扭曲，进而为年轻高管风险偏好的“代理冲突观”提供了实证证据。     

年轻高管与企业股价崩盘风险：来自“代理冲突观”的证据*

在企业纷纷实施高管年轻化战略的背景下，本文从股价崩盘风险的视角分析和检验了年轻高管风险偏好的经济后果及其作用机理。本文基于“个体认知观”和“代理冲突观”展开理论推演，采用中国沪深A股非金融上市公司的数据，检验发现，年轻高管会显著加剧企业未来的股价崩盘风险，且这种影响主要存在于民营企业，在国有企业并不显著。进一步针对具体作用机制的检验发现，年轻高管在投资决策中选择了更多能迅速提升个人收益的风险性投资项目，但在不能迅速提升个人收益的风险性投资项目上与年长高管没有显著差异。同时，年轻高管对股价崩盘风险的加剧效应仅仅存在于高管在上市公司领取薪酬的样本企业，且更高的独立董事比例能显著抑制年轻高管的股价崩盘风险加剧效应。这表明，年轻高管个体认知层面的风险偏好被其追求个人私利最大化的代理冲突所扭曲，进而为年轻高管风险偏好的“代理冲突观”提供了实证证据。     

中国股市与世界其他股市之间的大风险溢出效应:更正说明

《经济学季刊》2004年第3卷第3期第703—726页发表的洪永淼、成思危、刘艳辉、汪寿阳共同撰写的论文"中国股市与世界其他股市之间的大风险溢出效应"存在若干笔误,特作如下更正