虚拟团队构建过程中的人力资源问题探析

公司越来越意识到虚拟团队不仅可以提高公司的灵活性和对市场变化的响应速度,而且还能够降低成本。当组织计划建立虚拟团队时首先应当确定的团队任务及相关决策,其中的重点是使命描述、人员选拔以及任务设计。     

Islamic equity market integration and volatility spillover between emerging and US stock markets

The purpose of this paper is to study the conditional correlations across the US market and a sample of five Islamic emerging markets, namely Turkey, Indonesia, Pakistan, Qatar, and Malaysia. The empirical design uses MSCI (Morgan Stanley Capital International) Islamic equity index since it applies stringent restrictions to include companies. Indeed, two main restrictions must be met: (i) the business activity must be compliant with Shari’ah (i.e., Islamic law) guidelines and (ii) interest-bearing investments and leverage ratios should not exceed upper limits. Three models are used: multivariate GARCH BEKK, CCC, and DCC. The estimation results of the three models show that the US and Islamic emerging equity markets are weakly correlated over time. No sheer evidence supports that the US market spills over into the Islamic emerging equity markets. Besides interpreting the results in terms of weak market integration, the peculiar specificities of the Islamic finance industry and the admittance conditions to the MSCI Islamic equity index contribute to explaining them. Indeed, Islamic finance bans interest-bearing investments and imposes some rules, such as asset-backing, which has sizeable impacts on volatility spillover and shocks transmissions, alongside with the close linkage between real and financial sectors. These findings suggest that investors should take caution when investing in the Islamic emerging equity markets and diversifying their portfolios in order to minimize risk.     

Assessing time-varying stock market integration in Economic and Monetary Union for normal and crisis periods

In this paper, we examine the stock market integration process amongst 17 Economic and Monetary Union (EMU) countries from January 2002 to June 2013 over a normal period as well as for the Global Financial Crisis (GFC) and Eurozone Debt Crisis (EDC) periods. We classify the economies in three groups (A, B and C) based on their GDP to examine whether the economic size influences financial integration. Seven indicators are used for the purpose, namely, beta convergence, sigma convergence, variance ratio, asymmetric DCC, dynamic cointegration, market synchronisation measure and common components approach. The results suggest that large-sized EMU economies (termed as Group A) exhibit strong stock market integration. Moderate integration is observed for middle-sized EMU economies with old membership (termed as Group B). Small-sized economies (termed as Group C) economies seemed to be least integrated within the EMU stock market system. The findings further suggest presence of contagion effects as one moves from normal to crisis periods, which are specifically stronger for more integrated economies of Group A. We recommend institutional, regulatory and other policy reforms for Group B and especially Group C to achieve higher level of integration.     

Analysis of the volatility’s dependency structure during the subprime crisis

In this article, we test the hypothesis of contagion amongst sectors within the United States’ economy during the subprime crisis. The econometric methodology applied here is based on the dynamic conditional correlation model proposed by Engle (2002). Further, we applied several Lagrange multiplier (LM)-robust tests to test whether there were structural breaks in series’ dependency structures during the period of interest. Events theoretically classified as relevant to the crisis upshots as well as the interactions between the moments of the series were used as indicator functions to the referred structural breaks. The main conclusion of this study is that one can indeed observe contagion within almost all pairs of sectors’ indices. Thus, we conclude that the dependency structure of the sectors of interest has faced structural changes during the years of 2007 and 2008. Hence, diversification strategies as well as the risk analysis inherent to the portfolios’ management may have been drastically affected.     

基于DCC模型的上市银行系统风险实证研究

本文应用DCC多元GARCH模型分析上市银行股票价格的动态相关性,并以此作为银行整体风险的度量监测指标,在模型的构建中考虑了系统风险的时变特征。结果表明,相关系数的大小和动态变化能够对银行系统性风险起到一定的监测和预警作用。本次金融危机过后,银行间动态相关水平一直处于高位,表明投资者对未来银行资产质量和其潜在风险仍然存在担忧。     

FCC/DCC油在240万吨/年柴油精制装置中的应用

针对240万吨/年柴油精制装置反应器温升小,加热炉负荷高,燃料消耗高等问题,延安石油化工厂通过分析原因,增设了FCC/DCC油专线。原料油中掺炼FCC/DCC油后,反应器温升提高了8℃以上,有效解决了加热炉负荷高的问题,消除了安全隐患。     

The role of oil futures intraday information on predicting US stock market volatility

This study investigates the role of oil futures price information on forecasting the US stock market volatility using the HAR framework. In-sample results indicate that oil futures intraday information is helpful to increase the predictability. Moreover, compared to the benchmark model, the proposed models improve their predictive ability with the help of oil futures realized volatility. In particular, the multivariate HAR model outperforms the univariate model. Accordingly, considering the contemporaneous connection is useful to predict the US stock market volatility. Furthermore, these findings are consistent across a variety of robust checks.     

Correlation dynamics and international diversification benefits

Forecasting the evolution of security co-movements is critical for asset pricing and portfolio allocation. Hence, we investigate patterns and trends in correlations over time using weekly returns for developed markets (DMs) and emerging markets (EMs) over the period 1973–2012. We show that it is possible to model co-movements for many countries simultaneously using BEKK, DCC, and DECO models. Empirically, we find that correlations have trended upward significantly for both DMs and EMs. Based on a time-varying measure of diversification benefits, we find that it is not possible to circumvent the increasing correlations in a long-only portfolio by adjusting the portfolio weights over time. However, we do find some evidence that adding EMs to a DM-only portfolio increases diversification benefits.     

The nature and determinants of comovement between developed,emerging and frontier equity markets: Europe versus Asia‐Pacific

International investors are increasingly attracted towards emerging and frontier markets because of their potential to enhance diversification benefits of a global portfolio. This calls for a rigorous analysis of the nature and determinants of stock market comovement between developed, emerging, and frontier markets in Europe and Asia‐Pacific regions. The findings suggest that unlike their Asia‐Pacific counterparts, European developed, emerging, and frontier stock markets display a higher degree of comovement. Although Asia‐Pacific frontier markets provide good diversification opportunities, investors must be cautioned against their weak financial system. The volatility of returns, gross domestic product growth rate, and the 2008 global financial crisis (GFC) are the key determinants of stock market comovement in Europe. The mechanisms by which comovement in the Asia‐Pacific region is strengthened differ across markets. Comparative analysis of comovement and its determinants across different classes of equity markets and geographies is expected to provide valuable perspectives to global investors, portfolio managers, and policymakers.     

MGARCH models: Trade-off between feasibility and flexibility

Multivariate GARCH (MGARCH) models need to be restricted so that their estimation is feasible in large systems and so that the covariance stationarity and positive definiteness of conditional covariance matrices are guaranteed. This paper analyzes the limitations of some of the popular restricted parametric MGARCH models that are often used to represent the dynamics observed in real systems of financial returns. These limitations are illustrated using simulated data generated by general VECH models of different dimensions in which volatilities and correlations are interrelated. We show that the restrictions imposed by the BEKK model are very unrealistic, generating potentially misleading forecasts of conditional correlations. On the other hand, models based on the DCC specification provide appropriate forecasts. Alternative estimators of the parameters are important in order to simplify the computations, and do not have implications for the estimates of conditional correlations. The implications of the restrictions imposed by the different specifications of MGARCH models considered are illustrated by forecasting the volatilities and correlations of a five-dimensional system of exchange rate returns.