“金砖四国”股票市场间相依结构分析

金融市场间的相依关系及其结构分析是金融风险测度、资产组合管理等金融理论和实务中的一个重要问题,而基于线性相关系数是难以正确刻画非线性条件下金融资产间的相关结构,特别是尾相依关系。为研究"金砖四国"新兴股票市场间的相依结构,文章构建了一个混合Copula模型,对"金砖四国"股票市场间的相依结构进行建模分析,并将结果与单一阿基米德Copula模型进行了比较,表明混合Copula模型既能保留单一Copula模型的特性,更能灵活、全面地刻画变量间的相依关系。实证研究的结果表明:在样本数据期间,"金砖四国"股票市场间存在非对称相关关系,相依结构上存在差异;中国上证综指波动较为剧烈,与其它三国指数间以下尾相依为主;巴西、印度、俄罗斯三国股指间的相依结构相似,联动相关性相近,并无显著的下尾相依关系。     

Tail dependence and diversification benefits in emerging market stocks: an extreme value theory approach

This article examines tail dependence, the benefits of diversification and the relation between the two for emerging stock markets. We find most emerging equity markets are independent in limiting joint extremes. However, the dependence in finite levels of extremes is still much stronger than the dependence implied by multivariate normality. Therefore, simple correlation analysis can lead to gross underestimation of the chances of joint crashes in multiple markets. Assuming risk-averse investors guarding against extreme losses, diversification benefits are measured for each two-country optimal portfolio by the reduction in quantile risk measures such as value-at-risk and expected shortfall relative to an undiversified portfolio. It is shown that tail dependence measures developed from multivariate extreme value theory are negatively related to diversification benefits and more importantly can explain diversification benefits better than the correlation coefficient at the most extreme quantiles.     

Evidence of cross-asset contagion in U.S. markets

This study examines evidence of cross-asset contagion among REIT, money, stock, bond, and currency markets in the US from 2006 to 2012, which covers the subprime and European sovereign debt crisis. We apply the Granger causality test and a vector auto-regression to examine the change of causality structure. Our results show that contagion exists from medium-term bond markets to equity markets; REIT, money markets and short-term bond markets show little evidence of cross-asset contagion with other markets; and the currency market shows high co-movement and contagion with equity markets. Our findings provide more rewarding asset reallocating strategies for the investors who invest in both bond and equity markets before a crisis to consider reallocating their portfolio into REIT and money markets to benefit from diversification during a crisis period.     

Tail dependence analysis of stock markets using extreme value theory

Financial risk modelling frequently uses the assumption of a normal distribution when considering the return series which is inefficient if the data is not normally distributed or if it exhibits extreme tails. Estimation of tail dependence between financial assets plays a vital role in various aspects of financial risk modelling including portfolio theory and hedging amongst applications. Extreme Value Theory (EVT) provides well established methods for considering univariate and multivariate tail distributions which are useful for forecasting financial risk or modelling the tail dependence of risky assets. The empirical analysis in this article uses nonparametric measures based on bivariate EVT to investigate asymptotic dependence and estimate the degree of tail dependence of the ASX-All Ordinaries daily returns with four other international markets, viz., the S&P-500, Nikkei-225, DAX-30 and Heng-Seng for both extreme right and left tails of the return distribution. It is investigated whether the asymptotic dependence between these markets is related to the heteroscedasticity present in the logarithmic return series using GARCH filters. The empirical evidence shows that the asymptotic extreme tail dependence between stock markets does not necessarily exist and rather can be associated with the heteroscedasticity present in the financial time series of the various stock markets.     

Diamonds and precious metals for reduction of portfolio tail risk

ABSTRACT

We study the performance of diamonds compared to gold and other precious metals in mitigating the tail risk of a diversified equity market portfolio over the period June 2007 to October 2018. Our results display a diversification benefit of some diamond indices, which also improve the portfolio reward-to-risk ratio. To corroborate this evidence, we study the dependence structure and tail dependence of diamonds and a broad equity market portfolio and compare it to the dependence obtained with gold and other precious metals. Results from fitting a bivariate copula show that the average left tail dependence reaches its minimum when diamonds are used. We also show that using shares of diamond-mining companies does not provide the same benefits.     

The influence of foreign portfolio investment on informational efficiency: Empirical evidence from Central and Eastern European stock markets

This paper presents empirical evidence suggesting that foreign portfolio investment had a positive and significant influence on the informational efficiency of eleven Central and Eastern European stock markets during the period 1999–2010, regardless of the type of dependence – short or long run – taken into account when determining the measure of the degree of informational efficiency. Furthermore, considering the asymmetric effects of the portfolio flows, we have generally found a direct and strong relation between the net positive flows and the degree of informational efficiency. Our panel results also show that market capitalization represents a significant explanatory factor for the presence of short run dependence, while liquidity is associated with the presence of long run dependence. After isolating the common shocks in time, market volatility seems to have an even greater impact on efficiency.     

China's liberalizing stock market,crude oil,and safe-haven assets: A linkage study based on a novel multivariate wavelet-vine copula approach

China is the world's largest oil importer, and therefore the correlations between stock indices and highly volatile oil prices deserve close examination when investing in China's gradually liberalizing stock market. Another concern for international investors is whether safe-haven assets can reduce portfolio risks for investment in China. The paper makes two main contributions. First, we develop a novel method of examining a multivariate dependence structure by combining wavelet analysis with the vine copula model. Second, we apply the proposed methodology to study the correlations between China's liberalizing stock market, petroleum, and safe-haven assets at different frequencies. We find that the multidimensional dependence of these assets has been altered as a result of the 2008 global financial crisis. Moreover, the vine structures exhibit dependence patterns that vary over time horizons, indicating that the multidimensional dependence is sensitive to time scales.     

Portfolio Diversification Strategy Via Tail‐Dependence Clustering and ARMA‐GARCH Vine Copula Approach

This study proposes a diversified portfolio construction method based on the tail dependence between the financial assets and adopting both market prior information and the exports’ subject views. In this paper, tail‐dependence clustering was applied to divide candidate assets into different groups according to their tail dependence during the crisis period and the ARMA‐GARCH vine copula‐opinion pooling approach was applied to select the minimum Conditional Value‐at‐Risk portfolio according to the clustering results. The daily closed prices of the components of DAX 20 from 3 January 2006 to 20 December 2014 were studied to illustrate the methodology. The results reveal that more than 90% of 450 possible portfolios are modelled by D‐vine structure and Student's t‐copula dominates almost all the cases for pair copula selection. As Student's t‐copula captures the symmetric tail dependence, the 450 possible portfolios do not show stronger lower tail dependence than upper tail dependence. This study contributes by combining cluster analysis with portfolios selection. It uses vine copula to capture the dependence structure among assets. Finally, it offers a flexible method to describe market and offers a strategy to construct diversified portfolios by adding the investors’ information into portfolio selection procedure at the 1‐day forecast horizon.     

How to maximize golden opinions

In this article, we aim to model the level and structure of the dependence between the world's leading stock markets and those of the emerging market groups?–?Europe, Latin America and Far East. To this end we use a mixture model of Gaussian, Gumbel and Gumbel survival copulas. Our results indicate that none of the pairs of stock markets exhibit a right-tail dependence structure. All valid models exhibit a mixture of Gaussian and left-tail dependence structure. Our findings imply that Gaussian dependence structure is dominant in most of the models. The emerging equity markets in the European region exhibit the most significant dependence structure with the world leaders. Furthermore, most of the emerging equity markets have a significant dependence structure with the US stock market. We further compare our findings with the results of the conventional correlation coefficients and conclude the importance of using copula models in analysing the portfolio diversification opportunities. Our findings overall indicate two important remarks: First, the copula models reveal better indicators for global investors to establish a diversified portfolio; Second, international equity markets exhibit significant dependence, which leaves a smaller opportunity to benefit from international portfolio diversification.     

Entry costs and stock market participation over the life cycle

Several explanations for the observed limited stock market participation have been offered in the literature. One of the most promising is the presence of market frictions mostly in the form of fixed entry and/or transaction costs. Empirical studies point to a significant structural (state) dependence in the stock market entry decision, which is consistent with costs of this type. However, the magnitude of these costs is not yet known. This paper focuses on fixed stock market entry costs. I set up a structural estimation procedure which involves solving and simulating a life cycle intertemporal portfolio choice model augmented with a fixed stock market entry cost. Important features of household portfolio data (from the PSID) are matched to their simulated counterparts. Utilizing a Simulated Minimum Distance estimator, I estimate the coefficient of relative risk aversion, the discount factor and the stock market entry cost. Given the equity premium and the calibrated income process, I estimate a one-time entry cost of approximately two percent of the permanent component of the annual labor income. My estimated model matches the zero median holding as well as the hump-shaped age–participation profile observed in the data.     

The asymmetric price adjustment between REIT and stock markets in Asia-Pacific markets

This paper applies the threshold error correction model to examine the relationship for real estate investment trusts (REITs) and stock, and their asymmetric adjustment behaviors in six Asian/Pacific financial markets: Australia, Japan, Singapore, Taiwan, Korea, and Hong Kong. Our results show that there has been long-term equilibrium in REIT and stock indices in most of these markets. To earn exceptional profits, it is recommended that investors can sell (buy) the REITs when the indices of REITs are lower (higher) than equilibrium in Australia, Singapore and Taiwan; on the other hand, they should sell (buy) when the REIT market goes up (down) in Hong Kong and Japan. A causality test revealed that previous information about stocks predicted changes in the REITs in all the Asian/Pacific markets. One can also find that the lead–lag relationships are significant. The threshold EC model predicts two-way causality under both the regimes for the financial markets in most countries during all the sample periods. In addition, the adjustment speeds for the stock indices are faster than that for the REIT indices as disequilibrium occurs. This paper also finds that the previous mentioned trading strategies generally remained the same during the period of sub-prime mortgage crisis. However, the threshold EC model predicts one-way causality for both the regimes for the financial markets in most countries during this crisis period. In addition, we also find that the severe shock in REIT markets led investors in Australia and Taiwan to be more conservative during this period. The REIT indices had more effect on stock indices after the sub-prime mortgage crisis. According to the empirical results, we can infer that the degree of market imbalance and the occurrence of the sub-prime mortgage crisis induce the changes in the investment behavior of market participants.     

Index arbitrage and dynamics between REIT index futures and spot prices

This article contributes to the real estate literature by investigating the pricing relationship between REIT index futures and spot. Based on the cost-of-carry model, we first show that there exist three arbitrage regimes in Australia’s REIT spot-futures price dynamics. Further analysis indicates that the two thresholds, which separate the regimes, are largely consistent with the level dictated by transaction costs. We then estimate a threshold vector error correction model (TVECM). The results show that mean reversion of the mispricing error only takes place in the two outer regimes. Furthermore, we find evidence that REIT spot market is more informationally efficient than the futures market. Given its short history, it will take time for REIT index futures market to mature. Finally, we find that we can enhance hedging performance by accommodating the feature of threshold cointegration displayed by the data. As the futures-spot relationship differs across regimes, we can develop a hedging strategy by adjusting the hedge ratio based on arbitrage regimes. It leads to a greater variance reduction for the hedged portfolio than some conventional methods examined in the existing real estate literature.     

Dynamic linkages between stock markets: the effects of crises and globalization

This paper investigates changes in the dynamics of linkages between selected national stock markets during the period 1995–2009. The analysis focuses on the possible effects of globalization and differences between crisis and non-crisis periods. We model the dynamics of dependencies between the series of daily returns on selected stock indices over different time periods, and compare strength of the linkages. Our tools are dynamic copula models and a formal sequential testing procedure based on the model confidence set methodology. We consider two types of dependencies: regular dependence measured by means of the conditional Spearman’s rho, and dependencies in extremes quantified by the conditional tail dependence coefficients. The main result consists of a collection of rankings created for the considered subperiods, which show how the mean level of strength of the dependencies have been changing in time. The rankings obtained for Spearman’s rho and tail dependencies differ, which allows us to distinguish between the results of crises and the effect of globalization.     

A semiparametric approach to value-at-risk,expected shortfall and optimum asset allocation in stock–bond portfolios

This paper investigates stock–bond portfolios' tail risks such as value-at-risk (VaR) and expected shortfall (ES), and the way in which these measures have been affected by the global financial crisis. The semiparametric t-copulas adequately model stock–bond returns joint distributions of G7 countries and Australia. Empirical results show that the (negative) weak stock–bond returns dependence has increased significantly for seven countries after the crisis, except for Italy. However, both VaR and ES have increased for all eight countries. Before the crisis, the minimum portfolio VaR and ES were achieved at an interior solution only for the US, the UK, Australia, Canada and Italy. After the crisis, the corner solution was found for all eight countries. Evidence of “flight to quality” and “safety first” investor behaviour was strong, after the global financial crisis. The semiparametric t-copula adequately forecasts the outer-sample VaR. These findings have implications for global financial regulators and the Basel Committee, whose central focus is currently on increasing the capital requirements as a consequence of the recent global financial crisis.     

Portfolio management with tail dependence

Many publications, that treated with Portfolio Management, were devastating for all asset allocation models in the context of portfolios. The elimination of extreme events (asymmetric or tail dependence) during the portfolio construction process can reduce the skills of asset managers to reduce risk through diversification. The copula theory allows us to calculate an alternative to measure the dependence of extreme events in assets through the index lower tail dependence. We check that the strategies with tail dependence overcame Talmud rule, the Markowitz model and the model of Tu and Zhou by simulating 1,000 portfolios with 3, 5, 10 and 20 randomly selected assets from DJIA for the period 03/1990 until 12/2016. We conclude that models of tail dependence and Markowitz had more performance ex-ante than Talmud and the Tu and Zhou model for portfolios with 3, 5, 10 and 20 assets. Tail dependence models overcome Markowitz, in terms of cumulative return, in over 60% of months considered in the analysis. The results indicate that the Talmud rule should be discarded in a context of constructing portfolios with individual stocks ahead strategies with tail dependence.     

The relation between asset growth and the cross-section of stock returns: Evidence from the Chinese stock market

This study examines the effect of firm investment on stock returns by using data on the Chinese stock market. We find that stocks with higher investment experience lower future returns and there is an obvious investment effect in the Chinese stock market. The investment effect is stronger for firms that have higher cash flows, lower debt or for state-owned firms. We further explore the relation between investment and returns over the 3 years around portfolio formation. The results show that the high investment firms earn higher returns than low investment firms before portfolio formation; however the high investment firms earn lower returns than low investment firms after portfolio formation, such evidence is supportive of investor's overreaction explanation. Additionally, the stock returns don't necessarily decrease after investment, and the stock returns don't significantly positively correlate with firm profitability or book-to-market, so the result don't support risk-based explanation. Overall, both our portfolio sort and two-stage cross-sectional regression analysis show that behavioral finance theories are better than risk-based theories in explaining the investment anomaly. Evidence from the Chinese stock market provides a useful perspective to understand the debate on the investment anomaly.     

Oil price and Gulf Corporation Council stock indices: New evidence from time-varying copula models

Using a time-varying GJR copula approach, we determine the conditional dependence of the GCC stock indices on oil price between 2007 and 2016. We show how to improve the forecasting accuracy of the co-movement of energy and stock prices in an equally weighted portfolio. Contrary to prior findings, we demonstrate that due to the different co-movements across the GCC stock indices, portfolios of oil assets and several GCC stocks are less likely to be affected by systemic risk. The different co-movements across several stock indices over time provide different entry and exit points for stock investors. This approach is in line with the ‘buy low/sell high’ adage.     

Riding the Wave of Sentiment: An Analysis of Return Consistency as a Predictor of Future Returns

This article analyzes the degree to which return consistency in the past predicts future returns. I show that consistency is a strong predictive measure for future stock returns. In a portfolio context, positively consistent stocks exhibit positive future risk-adjusted returns, and negatively consistent stocks exhibit negative future risk-adjusted returns. The results are economically and statistically significant over multiple subperiods. Also, odd return behavior persists for nearly two years after portfolio formation. Stocks that have been consistently positive (negative) for longer time horizons have higher (lower) risk-adjusted returns during the followingmonththan those thathavebeenconsistent for shorter time periods. Finally, high consistency enhances momentum when the two factors are allowed to interact. Thus, there appears to be strong path dependence in the momentum effect, and consistency in stock returns appears to be an important component of return predictability.     

合格境外机构投资者投资行为的实证分析

根据QFII每季度公布的投资组合数据,对其交易行为进行研究,结果发现:QFII存在正向反馈策略和"羊群行为",而已有的研究证明,正向反馈策略和"羊群行为"不利于股票市场稳定。因此,要注意加强对QFII投资的监管,尤其是QFII信息披露的监管。     

Portfolio Choice and Liquidity Constraints*

We study the infinite‐horizon model of household portfolio choice under liquidity constraints and revisit the portfolio specialization puzzle. We show why the puzzle is robust to several model variations, and argue that positive correlation between earnings shocks and stock returns is unlikely to provide an empirically plausible resolution. We find that relatively small fixed costs for stock market entry are sufficient to deter stockholding because, for a plausible range of parameter values, households can achieve desired consumption smoothing with small or zero holdings of stocks. Such costs could arise from informational considerations, sign‐up fees, and investor inertia.