股指期货推出前后沪深300指数风险统计特征研究

股指期货是现代资本市场发展的产物,股指期货与现货的关系是学术界的研究的热点问题之一。文章介绍了风险价值VaR方法、非参数核密度估计理论以及VaR模型的回测评价原理,以我国股指期货推出前后一年间每一小时交易的高频数据为研究对象,运用非参数核密度估计法以及风险价值方法,计算在不同置信水平下的VaR值。在90%、95%以及99%置信水平下,股指期货推出前后,沪深300指数的收益率最大跌幅分别为0.921%、1.33%以及2.28%,变化为最大跌幅分别为0.871%、1.15%以及1.76%。表明在我国股指期货推出后,沪深300指数收益率的风险降低了。最后文章从市场效率,套利机制以及套期保值等视角对实证结果进行了分析。     

Risk assessment of oil price from static and dynamic modelling approaches

The price gap between West Texas Intermediate (WTI) and Brent crude oil markets has been completely changed in the past several years. The price of WTI was always a little larger than that of Brent for a long time. However, the price of WTI has been surpassed by that of Brent since 2011. The new market circumstances and volatility of oil price require a comprehensive re-estimation of risk. Therefore, this study aims to explore an integrated approach to assess the price risk in the two crude oil markets through the value at risk (VaR) model. The VaR is estimated by the extreme value theory (EVT) and GARCH model on the basis of generalized error distribution (GED). The results show that EVT is a powerful approach to capture the risk in the oil markets. On the contrary, the traditional variance–covariance (VC) and Monte Carlo (MC) approaches tend to overestimate risk when the confidence level is 95%, but underestimate risk at the confidence level of 99%. The VaR of WTI returns is larger than that of Brent returns at identical confidence levels. Moreover, the GED-GARCH model can estimate the downside dynamic VaR accurately for WTI and Brent oil returns.     

Forecasting realized volatility of crude oil futures with equity market uncertainty

This paper examines whether the equity market uncertainty (EMU) index contains incremental information for forecasting the realized volatility of crude oil futures. We use 5-min high-frequency transaction data for WTI crude oil futures and develop six heterogeneous autoregressive (HAR) models based on classical HAR-type models. The empirical results suggest that EMU contains more incremental information than the economic policy uncertainty (EPU) for forecasting the realized volatility of crude oil futures. More importantly, we argue that EMU is a non negligible additional predictive variable that can significantly improve the 1-day ahead predictive accuracy of all six HAR-type models, and improve the 1-week ahead forecasting performance of the HAR-RV, HAR-RV-J, HAR-RSV, HAR-RV-SJ models. These findings highlight a strong short-term and a weak mid-term predictive ability of EMU in the crude oil futures market.     

Testing the efficiency of the futures market for crude oil in the presence of a structural break

The efficiency of the futures market for crude oil has been the subject of significant study, with the basis regression representing a popular methodology. However, the parameters of this model are subject to a structural break, casting doubt on any conclusion regarding the efficiency of the futures market. To address this problem, this article employs a simple generalization which is capable of testing the efficiency of a futures market in the presence of a structural break. Using this approach, strong evidence of inefficiency is found in the one month futures contract for West Texas Intermediate for the period between 1985 and 2013, which is otherwise not detected.     

Covariance breakdowns and connectedness of crude oil futures markets with non-synchronous data

ABSTRACT

This article identifies the breakdowns in the covariance of three benchmark crude oil futures markets (WTI, Brent and Dubai) and investigates the changes of market connectedness across the breakdown periods. As the crude oil futures are traded in different regions, this article eliminates the non-synchronous trading data by employing the Vector Moving Average structure and the Bayesian data augmentation approach, which keeps the integrity of original data without changing its properties. The results show that there are significant breaks in the covariance structure of crude oil futures markets. The breakdown periods are consistent with the periods when the market volatilities are at high level and the returns are volatile. The changes of market connectedness are independent of the covariance states, which supports the globalization hypothesis for the crude oil market. The results also suggest that there is more information flow out of the WTI than to the WTI during the sample period, particularly during the breakdown periods in 2008–2009.     

我国产业集群全球价值链“低端锁定”战略风险及转型升级路径研究

产业集群发展为我国成为世界制造第一大国作出了巨大贡献。然而,我国产业集群在全球价值链分工体系中扮演着"打工者"角色,被长期锁定于全球价值链低端环节,这种低端锁定无论从宏观层面还是微观层面都给我国产业集群带来了巨大的战略风险,如何规避这些风险是理论界和实践人士必须研究并解决的重大课题。首先,阐述了我国产业集群全球价值链低端锁定的客观事实;其次,研究了全球价值低端锁定导致的战略风险;最后,提出了规避战略风险,实现战略转型升级的路径。