我国A股市场中的波动性之谜与市场情绪

本文使用Campbell和Shiller(1988)基于对数线性RVF的VAR非线性Wald检验方法对我国A股1994-2009期间的数据进行实证研究,结果表明样本期间我国A股股价相对其基础价值表现出"过度波动"的迹象,无论是常数超额收益率模型还是V-CAPM模型都无法对此进行解释。通过进一步定义市场情绪指数来分析这种"波动性之谜"现象的原因,结果发现市场情绪和股市"过度波动"之间存在相互作用机制,市场情绪能够对股价波动提供额外的解释。     

Stock Returns, Volatility, and Cointegration among Chinese Stock Markets

I. IntroductionA plethora of research has focused on therelationship between returns and volatility, andcointegration among major, well-established financial markets. It has been found that aninverse relationship exists between an individualfirm’s stock return volatility and itsstockprice. There are two popular explanations: the first one is related to the leverage effect. Itasserts that a decrease in afirm’s stock price increases the firm’s debt ratio (or decreasesthefirm’s equity ratio)…     

Price Common Volatility or Volume Common Volatility? Evidence from Taiwan's Exchange Rate and Stock Markets

This paper investigates the common volatility structure of stock and exchange rate markets of Taiwan. The two markets are often linked together and we are interested in knowing whether price or volume is a good proxy to pursue this issue. We claim that Taiwanese government interventions distort the timing of conventional price volatility clustering in the two markets. The unrestricted trading volumes reveal more information regarding the market than price. We find that common volatility does exist in the stock and exchange markets and this fact is uncovered more easily by using trading volume than by using prices.     

Examining Stock Volatility in the Segmented Chinese Stock Markets: A SWARCH Approach

Abstract

This study adopts the SWARCH model to examine the volatile behavior and volatility linkages among the four major segmented Chinese stock indices. We find strong evidence of a regime shift in the volatility of the four markets, and the SWARCH model appears to outperform standard generalized autoregressive conditional heteroskedasticity (GARCH) family models. The evidence suggests that, compared with the A-share markets, B-share markets stay in a high-volatility state longer and are more volatile and shift more frequently between high- and low-volatility states. In addition, the relative magnitude of the high-volatility compared with that of the low-volatility state in the B-share markets is much greater than the case in the two A-share markets. B-share markets are found to be more sensitive to international shocks, while A-share markets seem immune to international spillovers of volatility. Finally, analyses of the volatility spillover effect among the four stock markets indicate that the A-share markets play a dominant role in volatility in Chinese stock markets.     

African Stock Markets: Efficiency and Relative Predictability

The weak form of the efficient markets hypothesis is tested for eight African stock markets using three finite‐sample variance ratio tests. A rolling window captures short‐horizon predictability, tracks changes in predictability and is used to rank markets by relative predictability. These stock markets experience successive periods when they are predictable and then not predictable; this is consistent with the adaptive markets hypothesis. The degree of predictability varies widely: the least predictable African stock markets are those located in Egypt, South Africa and Tunisia, while the most predictable are in Kenya, Zambia and Nigeria.     

Unregulated Stock Markets in Second Life

SLCapex is a stock exchange owned and operated by “residents” of the online virtual world Second Life. Despite its almost complete lack of regulation and legal protections against fraud or insider trading, issuers were able to raise approximately US$145,000 from investors, which grew to US$900,000 in market value before plummeting, resulting in overall investor returns of ?71%. Investors in large issuances lost more than investors in small issuances, and small investors experienced more severe losses relative to large investors when more money was at stake, indicating that the market did a poor job of protecting investors from issuers and of providing a level playing field for investors. Theories from financial economics can explain the markets' poor performance in the absence of regulatory and legal institutions, but they cannot easily explain why issuers were able to raise capital in such a setting.     

Interaction between Foreign and Domestic Investors in the Korean Stock and Futures Markets*

The present paper analyzes the behavioral relations of major investor groups in the stabilized Korean stock and futures markets after the 1997 Asian financial crisis. Investor groups cannot be classified as positive or negative feedback traders on market returns when both stock and futures markets are considered, which is inconsistent with the results in Ghysels and Seon (2005). Foreign investors and domestic institutions tend to take opposite positions in both markets. The impact of foreign investors on the basis change is significantly negative in the futures market, whereas domestic institutions have a negative relation in the stock market. This supports the view that selling activity of foreign investors in the futures market pulls the futures price down compared with the index value and, consequently, induces the reverse cash‐and‐carry trade of domestic institutions. This relationship, which negatively influenced the Korean economy during the crisis, as shown in Ghysels and Seon (2005), still exists in the Korean financial markets.     

中国与国际证券市场间的风险传导模式——基于方差因果性研究的新证据

在全球金融市场一体化程度不断加深和我国金融市场入世后进一步开放的背景下，我国与国际主要证券市场间的投资信息与风险联系日益增强。本文分别采用考察方差波动因果性联系的两阶段CCF和multivariate—GARCH（BEKK形式）方法，以近年来处于高涨阶段的沪深股市与同期世界主要股票市场的日交易数据为研究对象，对其相互间的信息传导模式进行了比较性分析。研究表明，随着中国证券市场主要制度改革的顺利完成和市场规模的不断扩张，自2006年以来中国对国际主要证券市场的风险和信息传导效应相当显著。也就是说，继国际贸易与直接投资领域之后，依托于长期快速发展的宏观经济基础上的中国证券市场，事实上也已经开始在世界市场中扮演着越来越重要的角色。与此相反，样本期内国际主要市场的波动对我国市场的影响却并不明显。研究表明相关监管机构和微观主体需要密切关注市场中可能存在的投资风险。     

Zombie Firms and Soft Budget Constraints in the Chinese Stock Market*

The growth of zombie firms has caused increasing concern. The present study seeks to understand why zombie firms have been emerging in recent 10 years and to further explore the mechanisms of their formation. Based on a dataset of Chinese listed companies from 2012 to 2016 and empirical analysis, the present study ascribes the prevalence of zombie firms to soft budget constraints. After using a modified identification model in the Chinese context, we concluded that zombie firms have access to some external resources such as credit support from banks and governmental subsidies, substantiating soft budget constraints among zombie firms. To explain this phenomenon, further analysis reveals that zombie firms bear a heavier policy burden by hiring excess employees, which will bring them more subsidies and a stronger relationship with government in return. This result indicates that policy burden is the reason for soft budget constraints, which exacerbates the zombie firm problems in China.     

Global Financial Crises and Time‐Varying Volatility Comovement in World Equity Markets

This paper studies volatility comovement in world equity markets between 1994 and 2008. Global volatility factors are extracted from a panel of monthly volatility proxies relating to 25 developed and 20 emerging stock markets. A dynamic factor model (FM) is estimated using two‐year rolling‐window regressions. The FM's time‐varying variance shares of global factors map variations in volatility comovement over time and across countries. The results indicate that global volatility linkages are significantly stronger during financial crisis periods in Asia (1997‐1998), Brazil (1999), Russia (1998) and the United States (2000, 2007‐2008). Emerging markets are weakly synchronised with world volatility in comparison with developed markets. In particular, emerging market comovement is significantly lower than developed market comovement during the Asian and US sub‐prime crises. This suggests a degree of decoupling of emerging markets from the global drivers of volatility during these periods.     

The Korean stock market volatility during the currency crisis and the credit crisis

This paper studies the volatility of the Korean stock market during the Asian currency crisis of 1997–1998 and the global credit crisis of 2008–2009. We use a fad model with Markov switching heteroskedasticity, which was first proposed by Kim and Kim (1996). Using the monthly data from January 1980 to October 2009, we find that the volatility of the transitory component of the stock return, or fads, increased during the currency crisis, but did not rise much during the credit crisis. It implies that the stock price fluctuations were not driven by irrational sentiments during the recent global crisis as much as during the former crisis. However, when we consider the dollar value of the Korean stock index in order to estimate the volatility that foreign investors confront, we find that the volatility of the transitory component was raised during the credit crisis as well as during the currency crisis. That is, foreign investors experienced greater volatility than domestic investors in the recent financial market turmoil. This asymmetric volatility that domestic and foreign investors face is one of the characteristics of the credit crisis.For more detailed analysis, the same model was applied to the weekly data from January 2005 to October 2009 and provided the result that the data measured by won–dollar exchange rates were more increased than the raw data. It holds that foreign investors confronted much greater volatility than domestic investors while the stock volatility was relatively lower in the credit crisis state than in the currency crisis state.     

Impacts of Internet Stock News on Chinese Stock Markets

The research of impacts of the intemet stock news （ISN） on the Chinese stock markets emerges with the era of the popular usage of the intemet. In this paper, the ISN is empirically related to the stock returns based on the neural networks. Experiments demonstrate the probable relations, hinted by the neural networks. The results are helpful in probing the microstructure of the Chinese stock markets.     

中国股票市场波动率分解及长期趋势研究

Campbell等（2001）为实证研究市场的长期趋势特征提出了市场波动率分解模型，其特点是将波动率按成因进行分解并且该分解不依赖于β系数。采用该模型，本文将我国股票市场1991至2004年的波动率实证分解为市场波动率、行业波动率和公司波动率。研究了我国股票市场三种波动率的长期变化趋势。与美国市场相比（美国市场1962至1997年间市场和行业波动率保持稳定而公司波动率增长了一倍），本文的实证结果表明：我国市场1991至2004年间市场、行业和公司波动率均存在显著的下降趋势；表现出了与国际市场不同的趋势特点；随着时间的推进，我国股票市场在不断成熟、市场效率不断提高。进一步的研究表明，1998年后我国股票市场中市场波动率最大。公司波动率略小，而行业波动率则远小于前两者。本文的研究结论将为政策制定者和投资组合风险管理者提供宏观借鉴，我国投资风险管理的战略重点首先应对冲市场风险，其次分散公司风险。     

Poverty and firewood consumption: A case study of rural households in northern China

This paper discusses the determinants of firewood consumption in a poor township in rural northern China, with a special focus on the relationship between households' economic wealth and firewood consumption. We find strong support for the poverty–environment hypothesis since household economic wealth is a significant and negative determinant of firewood consumption. Firewood can therefore be considered as an inferior good for the whole population in the rural area under study, although further evidence shows that at the top of the wealth distribution, there might be a floor effect in the decreasing firewood consumption. Besides economic wealth, our analysis also shows that the own-price effect is important in explaining firewood consumption behavior, the price effect gaining importance with rising incomes. Finally, increasing education is also found to be a key factor in energy consumption behavior, especially when dealing with energy source switching behavior.     

收益波动与随机冲击的非对称性影响：中国与美国股票市场的对比

通过讨论股票收益与随机;中击之间的关系,对中国股票市场和美国股票市场进行了对比研究。研究中使用了中国上海和深圳股票市场1990年12月31日至2005年12月30日的两市A股算术平均周指,以及美国股票市场1973年1月2日至2004年月12月30日的标准普尔500周指。在进行经验研究的过程中,分别使用了线性GARCH模型和GJR—GARCH模型计量股票收益的条件波动——即模型中的条件方差。研究发现,中国股票市场自1990年——1995年波动剧烈,之后波动趋于平缓,而美国股票市场在研究期间内收益波动一直处于一定范围内。同时还发现,美国股票市场的随机冲击对股票收益产生非对称性影响,即负冲击使股票收益产生的波动大于正冲击。而在中国股票市场却找不到相似的证据。鉴于对中国股票市场收益波动的研究结果,在剔除1996年以前的数据之后又进行了扩展研究,但是似然比率检验结果表明,正冲击对股票收益的影响还要略强于负冲击。     

Systemic Risks Spillovers and Interdependence among Stock Markets: International Evidence with Covar‐Copulas

Empirical studies have provided ample evidence on the potential benefits of international diversification with portfolios that consist of both domestic and foreign assets. This coupled with sudden and periodic crashes in global and developed equity markets have stimulated the interest of investors to diversify across markets that have the potential to provide decorrelation with global markets during turbulent periods. At the same time, international diversification may intensify cross‐border listing of stocks with its antecedent implication of shocks transmission. The above have engendered renewed interest among researchers to explore the dependence levels and spillover effects of shocks among emerging and developed equity markets. This paper examines tail dependence structure and (extreme) systemic risks spillover effects among international equity markets using advanced econometric techniques that underpin the modelling of asset returns. We find evidence of low positive significant dependencies between all African markets and their developed counterparts, except for Egypt. Although no evidence of spillover effects to the markets in Africa was found, both unidirectional and bi‐directional causality between some African and developed equity markets is found, albeit with differences. We are unable to ascribe the dynamics in the causality structure to level of market integration. It is inferred that the degree of individual local markets interdependence with developed counterparts may reflect the relative size, liquidity and degree of foreign investors' participation.     

Timeliness of Annual Reports of Chinese Listed Companies

The timeliness of annual reports has received serious attention by the Chinese regulatory and professional bodies in recent years. Using 8294 company reports from the Chinese listed companies during 1993–2003, this paper analyzes the timeliness of annual reports by first examining the trend of reporting lags, separating the effects of ‘good’ and ‘bad’ news on timeliness, and then by using a multivariate regression to identify the determinants of reporting lags. It is found that there is a significant improvement on timeliness of reports although the shortening of reporting lags shows a U-shape over the data period. There is strong evidence that reporting lags were related to firm performance as bad news tended to hold back timely release of corporate reports. It is interesting to note that government policies have also played an important role in improving timeliness of corporate annual reporting in China but much more work needs to be done to make sure that listed companies provide more timely and reliable reports to investors and regulatory authorities.     

中国股市收益分形分布的实证研究

近年来,分形分布在金融市场中的研究和应用逐渐引起研究者的浓厚兴趣。本文借助分形分布理论对中国股票市场的收益分布特性进行了实证研究,估计出了分形分布的参数,绘制了分形分布的密度曲线,并对其进行了拟合检验。实证结果表明,分形分布能较好地拟合中国股票市场的收益序列。     

中国股票市场财富效应微弱研究

本文首先从实证上揭示了中国股票市场财富效应微弱的现实，在此基础上，本文从股市财富效应发挥所需要的宏观条件、市场环境及微观基础等角度，运用信息经济学和博弈论的有关原理，在理论上分析了股市财富效应的实现条件，并揭示出上市公司的质量是股市财富效应正常发挥的根基性条件。在这些研究的基础上，本文进一步研究了中国股市财富效应微弱的原因，并得出了有意义的推论。     

Relative Performance Incentives and Price Bubbles in Experimental Asset Markets

We study experimental markets in which participants face incentives modeled upon those prevailing in markets for managed funds. Each participant's portfolio is periodically evaluated at market value and ranked by relative performance as measured by short‐term paper returns. Those who rank highly attract a larger share of new fund inflows. In an environment in which prices are typically close to intrinsic value, the effect of these incentives is mild. However, in an environment in which markets are prone to bubble, mispricing is greatly exacerbated by relative performance incentives and becomes even more pronounced with experience.