Random matrix application to correlations amongst the volatility of assets

In this paper, we apply tools from random matrix theory (RMT) to estimates of correlations across the volatility of various assets in the S&P 500. The volatility inputs are estimated by modelling price fluctuations as a GARCH(1,1) process. The corresponding volatility correlation matrix is then constructed. It is found that the distribution of a significant number of eigenvalues of the volatility correlation matrix matches with the analytical result from RMT. Furthermore, the empirical estimates of short- and long-range correlations amongst eigenvalues, which are within RMT bounds, match with the analytical results for the Gaussian Orthogonal ensemble of RMT. To understand the information content of the largest eigenvectors, we estimate the contribution of the Global Industry Classification Standard industry groups to each eigenvector. In comparison with eigenvectors of correlation matrix for price fluctuations, only few of the largest eigenvectors of the volatility correlation matrix are dominated by a single industry group. We also study correlations between ‘volatility returns’ and log-volatility to find similar results.     

高校体育运动环境与氛围建设的构思理念

高校体育运动环境的好坏直接影响到在校学生对体育运动参加的热情和积极性,良好的体育运动环境能够为广大学生营造良好的学校体育氛围,对培养学生对体育的认识以及对终身体育意识的形成非常有利。根据高校体育运动环境与氛围的建设,有助于高校学生更多地参与到体育运动中去。     

内蒙古财经学院学生课外体育活动现状与调查分析

现阶段,社会各界人士对"健康"这一词给予高度评价,尤其是"健康第一"的指导思想被大众所接受。从教育这个角度出发,高校学生身心健康问题越来越受到社会的关注。学校体育文化酝酿着丰富的内容和崇高的文化价值,对高校学生的身心健康有积极的影响。通过对内蒙古财经学院学生课外体育活动现状的调查与分析,探讨了新形势下以学校现有的条件如何进一步推动体育工作,以及培养学生对体育的兴趣和开展好课外体育活动的新途径。根据这些内容具体提出了几点建议。     

基于GLM的未决赔款准备金评估的随机性链梯法

为度量未决赔款准备金评估结果的波动性,需要研究随机性评估方法。基于GLM的随机性方法,得到准备金估计及预测均方误差。特别地,在过度分散泊松模型中,分别应用参数Bootstrap方法和非参数Bootstrap方法,得到两种方法下未决赔款准备金的预测分布,进而由该分布得到各个分位数以及其它分布度量,并通过精算实务中的数值实例应用R软件加以实证分析。实证结果表明,两种Bootstrap方法得到的参数误差、过程标准差、预测均方误差都与解析表示估计的结果很接近。     

社会保障对收入分配差距的调节效应——基于陕西省宝鸡市住户调查数据的实证研究

社会保障具有重要的收入再分配功能,在很多国家社会保障都是调节居民收入分配差距最重要的手段。本文对陕西省宝鸡市住户调查数据的实证研究表明,社会保障转移性收入缩小了居民收入分配差距,使城乡居民收入的基尼系数下降了4.5%,其中城镇居民基尼系数下降22.8%,农村居民基尼系数下降1.82%。但由于农村居民获得的社会保障转移性收入远远低于城镇居民,从而导致城乡收入差距上升23.17%。为抑制收入分配差距的进一步扩大,中国应重视社会保障对收入分配的调节作用,进一步增加社会保障的财政投入。尤其要加大对农村社会保障的财政投入,尽快扭转社会保障对城乡收入差距的逆向调节。     

创建大学生失业保险制度刍议

当前,大学生失业现象已成为社会关注的热点问题。它不仅对个人、家庭和社会产生了巨大的负面影响,也造成各种资源的极大浪费。本文在对大学生失业的现状、原因及其后果分析的基础上,认为创建大学生失业保险势在必行,并对大学生失业保险制度提出了一些建议。     

Factor state–space models for high-dimensional realized covariance matrices of asset returns

We propose a dynamic factor state–space model for high-dimensional covariance matrices of asset returns. It makes use of observed risk factors and assumes that the latent integrated joint covariance matrix of the assets and the factors is observed through their realized covariance matrix with a Wishart measurement density. For the latent integrated covariance matrix of the assets we impose a strict factor structure allowing for dynamic variation in the covariance matrices of the factors and the residual components as well as in the factor loadings. This factor structure translates into a factorization of the Wishart measurement density which facilitates statistical inference based on simple Bayesian MCMC procedures making the approach scalable w.r.t. the number of assets. An empirical application to realized covariance matrices for 60 NYSE traded stocks using the Fama–French factors and sector-specific factors represented by Exchange Traded Funds (ETFs) shows that the model performs very well in- and out of sample.     

深化大学生思想道德建设的思考

培养什么人,如何培养人,是高等教育的一个重大课题。在新的形势下,大学生的思想政治状况究竟如何?大学生思想教育究竟面临什么样的挑战?如何切实加强大学生思想政治教育工作?是我们作为高校教师特别是专门从事学生管理工作的教师应该重视和思考的问题。     

对女大学生参与体育艺术类课程学习动机的研究

高校体育艺术类课程能最大限度地实现教学与满足女大学生的健身学习需要,本文对课程相关的各类学习参与动机因素进行了分析,为今后课程的发展提供了一定的理论参考依据。     

Fractals in trade duration: capturing long-range dependence and heavy tailedness in modeling trade duration

Several studies that have investigated a few stocks have found that the spacing between consecutive financial transactions (referred to as trade duration) tend to exhibit long-range dependence, heavy tailedness, and clustering. In this study, we empirically investigate whether a larger sample of stocks exhibit those characteristics. We do so by comparing goodness of fit in modeling trade duration data for stable distribution and fractional stable noise based on a procedure applying bootstrap methods developed by the authors with several alternative distributional assumptions in modeling trade duration data. The empirical results suggest that the autoregressive conditional duration model with stable distribution fits better than other combinations, while fractional stable noise itself fits better for the time series of trade duration. Our result is consistent with the general findings in the literature that trade duration is informative and that short trade durations move prices more than long trade duration. In addition, our result confirms the advantage of fractal models in the study of roughness in trade duration and provides some evidence for duration dependence. S. Rachev’s research was supported by grants from the Division of Mathematical, Life and Physical Science, College of Letters and Science, University of California, Santa Barbara, and the Deutschen Forschungsgemeinschaft. W. Sun’s research was supported by grants from the Deutschen Forschungsgemeinschaft. P.S. Kalev’s research was supported with a NCG grant from the Faculty of Business and Economics, Monash University. Data are supplied by Securities Industry Research Center of Asia-Pacific (SIRCA) on behalf of Reuters. The first draft of this paper was presented at the International Conference on High Frequency Finance 2006; the authors would like to thank the conference participants for their valuable comments.