分形市场假说与股票市场的有效性分析

主流的金融计量理论是以价格的随机游走和收益的正态分布假设为基础的。而分形市场研究认为价格是分形,价格遵循有偏随机游走,并用分形分布描述收益的分布规律。在分形研究的框架下,作为主流有效市场假说的替代理论,分形市场假说用不同投资期水平下的投资者对信息的不同评估来解释价格行为的分形机制,也启发我们从动态的和相对的角度去思考股票市场的有效性问题。     

Stock Prices, Output and the Monetary Regime

Should monetary policy react to stock prices? The answer depends on whether stock prices are good predictors of future economic activity. Using long annual time-series data for the G-7 countries, data going back over 150 years for some countries, we find that stock prices do not systematically predict output growth regardless of the monetary regime in effect. We also find no evidence of a nonlinear relationship between stock prices and output except during the gold standard, when stock price booms and busts had some predictive power for output growth volatility.     

未预期货币政策冲击与股票价格

货币政策影响股票价格的理论机制清晰确凿,实证检验的主要挑战是资本市场对货币政策冲击可能存在事先预期。基于货币政策公告后的国债收益率变动,文章识别了未被市场充分预期的货币政策冲击,并实证考察了 2000 年以来历次法定存款准备金率调整和贷款基准利率调整,发现未预期货币政策冲击对股票市场价格产生显著影响,1% 的未预期“降准”会引起上证指数和深证综指上涨 1.39% 和 1.415%,1% 的未预期“降息”会引起上证指数和深证综指上涨 0.662% 和 1.01%。     

深圳证券市场中长期价格反转现象的实证研究

有效市场假说随着时代的发展逐渐受到质疑,众多学者从理论与实证角度的论证中发现,证券市场并非那么有效。本文以深圳证券市场价格反转现象为研究对象,通过实证检验发现,深圳证券市场也存在有效市场假说所谓的“异象”一价格反转现象。     

China＇s Stock Market： Inefficiencies and Institutional Implications

The dramatic movements of China＇s stock market in the past two and a half years have renewed debate among academics over the efficiency of China＇s stock market. The present paper tests the efficiency of China＇ s stock market. The realization of efficient markets requires the effective operation of a complete set of macro and micro mechanisms. However, such mechanisms are not only incomplete in China＇ s stock market, but are also ineffective because of the prevalence of institutional deficiencies.     

Institutional Ownership and the Extent to which Stock Prices Reflect Future Earnings*

Articles in the financial press suggest that institutional investors are overly focused on current profitability, which suggests that as institutional ownership increases, stock prices reflect less current period information that is predictive of future period earnings. On the other hand, institutional investors are often characterized in academic research as sophisticated investors and sophisticated investors should be better able to use current‐period information to predict future earnings compared with other owners. According to this characterization, as institutional ownership increases, stock prices should reflect more current‐period information that is predictive of future period earnings. Consistent with this latter view, we find that the extent to which stock prices lead earnings is positively related to the percentage of institutional ownership. This result holds after controlling for various factors that affect the relation between price and earnings. It also holds when we control for endogenous portfolio choices of institutions (e.g., institutional investors may be attracted to firms in richer information environments where stock prices tend to lead earnings). Further, a regression of stock returns on order backlog, conditional on the percentage of institutional ownership, indicates that institutional owners place more weight on order backlog compared with other owners. This result is consistent with institutional owners using non‐earnings information to predict future earnings. It also explains, in part, why prices lead earnings to a greater extent when there is a higher concentration of institutional owners.     

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.     

Contrarian Investment in the Dutch Stock Market

The efficient markets hypothesis states that at any times security prices fully reflect all available information. Contrarian investment strategies do not recognize the efficiency of capital markets. They call for buying undervalued stocks, i.e. stocks with a low price relative to their fundamentals. The idea behind such a strategy is to take advantage of the extrapolation behaviour of naive investors. Using a fresh and extensive data set from the Dutch stock market, we found that these strategies yield an outperformance without a higher risk. Our results make it hard to maintain the efficient market hypothesis.     

Reinvestigating the Oil Price–Stock Market Nexus: Evidence from Chinese Industry Stock Returns

The present study investigates the influence of international oil prices on China's stock market returns across 29 different industries. The paper attempts to account for any structural breaks and nonlinearity in this relationship. The results reveal that the effect of changes in the international price of oil on stock returns differs substantially across industries. The stock returns of the coal, chemical, mining and oil industries are found to be positively affected by crude oil price movements. Conversely, electronics, food manufacturing, general equipment, pharmaceuticals, retail, rubber and vehicle industries are found to be negatively affected by movements in the price of crude oil. The results of the estimations also suggest that the majority of Chinese industries have been significantly affected by oil prices since 2004. The influence of international oil prices on Chinese stocks also has a stronger effect in the presence of high volatility but the effect varies across industries.     

Transmission of Stock Prices and Volatility from the Influential Major Markets on the Emerging Market: A Case Study of the Korean Stock Market

Abstract

This study investigates how the 1997 crisis has changed the Korean market by focusing on price and volatility spillovers from the US, Chinese, and Japanese markets. Using the exponential general autoregressive conditional heteroskedastic (EGARCH) model, new information on stock prices originating in the US market was transmitted to the Korean market for all periods. The price spillover effect from the Japanese market to the Korean market became stronger from the crisis period. Asymmetry in the spillover effect on market volatility was more pronounced in the Korean market after the financial crisis.     

我国股票市场流动性与股价的动态关系研究

关于股票市场中流动性与股价之间的关系,学术界一直存在争议,传统模型往往只能片面地反映。文章利用状态空间模型以及沪深300指数与中证500指数的数据,对我国股票市场流动性和股价之间的动态关系进行了深入研究。实证结果表明:第一,我国股票市场流动性对股价存在影响,在代表大市值企业的沪深300市场中,两者为正向关系且波动幅度较小;在代表小市值企业的中证500市场中,两者为负向关系且波动幅度较大。第二,在两个市场中股价对股票市场流动性都存在正向的影响关系,且以中证500指数为代表的小盘股市场表现更为明显。     

Stock prices in Japan rise at night

Examining daily data of the Nikkei Average from 23 October 1986 to 20 January 1998, I find that although the mean of the rate of change during the trading hours (RT) is negative, the mean during non-trading hours (RNT) is significantly positive. I also find that (1) RT has a stable relationship with Japanese economic fundamentals while RNT does not, (2) RNT reflects US economic fundamentals, though weakly, and (3) if the previous trading hours reflected bearish trading, then the bearish sentiment is not taken over to opening time, as opposed to when the previous trading hours reflect a more bullish attitude. A possible cause of the positive RNT is optimism of Japanese investors, especially that of securities companies.     

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。     

浅析流动性过剩背景下的股市泡沫

流动性过剩已成为中国经济发展中的一个热点问题.文章分析了形成流动性过剩的国际和国内两个方面的原因.对于流动性过剩导致了中国股市繁荣的现状,文章提出了防范股市泡沫的措施.     

推进我国多层次股票市场建设的研究

2002年以来我国股票市场融资能力下降,关键原因就是单一的、行政管制的主板市场并没有很好地满足多层次的企业融资需求.文章简要分析了我国股票市场融资的现状及存在的问题,提出我国发展多层次股票市场的必要性,借鉴海外多层次股票市场体系,对我国构建完整的多层次股票市场进行了思考.     

Efficiency,Cointegration and Contagion in Equity Markets: Evidence from China,Japan and South Korea*

This paper empirically examines whether three East Asian stock markets, namely, those of China, Japan and South Korea, are individually and/or jointly efficient, and whether contagion exists between the cointegrated markets. While individual market efficiency is examined through testing for the random walk hypothesis, joint market efficiency is examined through testing for cointegration and contagion. The present study finds that the hypothesis of individual market efficiency is strongly rejected for the Chinese stock market, but not for the Japanese and the South Korean stock markets. However, when testing for cointegration, market efficiency is strongly rejected for all these markets. We take a simple case of contagion and find that although there is a long‐term relationship among the three markets, the contagion hypothesis cannot be rejected only between Japanese and South Korean stock markets, indicating short‐run portfolio diversification benefits from these two markets.     

MACROECONOMIC UNCERTAINTY AND CONDITIONAL STOCK MARKET VOLATILITY IN SOUTH AFRICA*

This paper analyses how systematic risk emanating from the macroeconomy is transmitted into stock market volatility using augmented autoregressive Generalised Autoregressive Conditional Heteroscedastic (AR‐GARCH) and vector autoregression (VAR) models. Also examined is whether the relationship between the two is bidirectional. By imposing dummies for the 1997‐1998 Asian and the 2007‐2009 sub‐prime financial crises, the study further analyses whether financial crises affect the relationship between macroeconomic uncertainty and stock market volatility. The findings show that macroeconomic uncertainty significantly influences stock market volatility. Although volatilities in inflation, the gold price and the oil price seem to play a role, it is found that volatility in short‐term interest rates and exchange rates are the most important, suggesting that South African domestic financial markets are increasingly becoming interdependent. Finally, the results show that financial crises increase volatility in the stock market and in most macroeconomic variables, and, by so doing, strengthen the effects of changes in macroeconomic variables on the stock market.     

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.     

Stock Market Linkages in South–East Asia

The present paper examines the linkages between the South–East Asian stock markets following the opening of the stock markets in the 1990s. No evidence was found to indicate a long–run relationship among the South–East Asian stock markets over the period 1988–1997; however, correlation analyses indicate that the South–East Asian stock markets are becoming more integrated. The results from the time–varying parameter model also show that the stock market returns of Indonesia, the Philippines and Thailand had all become more closely linked with that of Singapore.     

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.