Copula函数的选择：方法与应用

针对目前Copula函数在实际应用中的选择问题,本文通过非参数法得到了它们的分布函数图及其经验分布图并进行了比较,然后利用一种解析法对其进一步的选择,并通过Q-Q图比较了各种模型的拟合程度,最后进行了拟合优度检验,得到了最优的Copula。最后对国内的上证A股指数和上证B股指数进行了实证分析,结果体现了该方法的有效性。  

沪深股市相关结构分析研究

在金融市场风险分析中,对金融资产相关结构的讨论有着重要意义,从而引出对如何选取好的相关结构模型来捕捉金融资产间的相关变化规律的讨论。针对这一问题,我们用混合相关结构函数Copula对上海、深圳股票市场进行了相关分析研究,用极值分布刻画了每支股票的边缘分布,用两步估计法对Copula中的参数进行了估计。分析结果表明:混合Copula相关结构能够捕捉金融市场间相关性变化规律,比单个Copula相关结构更灵活,更能全面地反映市场间非对称变化的相关程度和模式,此方法还可以推广到对多种金融资产收益率进行相关性分析。  

中国股市相依结构测定初探

提出了中国股市测定copula相依结构的一般方法,并结合中国股市的实际数据作了分析.在假定边际分布为正态分布时,得到了描述工业指数与商业指数相依结构的较好copula结构为正态copula族.  

Additivity properties for Value-at-Risk under Archimedean dependence and heavy-tailedness

Mainly due to new capital adequacy standards for banking and insurance, an increased interest exists in the aggregation properties of risk measures like Value-at-Risk (VaR). We show how VaR can change from sub to superadditivity depending on the properties of the underlying model. Mainly, the switch from a finite to an infinite mean model gives a completely different asymptotic behaviour. Our main result proves a conjecture made in Barbe et al. [Barbe, P., Fougères, A.L., Genest, C., 2006. On the tail behavior of sums of dependent risks. ASTIN Bull. 36(2), 361-374].  

Continuous dependence on the Soret coefficient for double diffusive convection in Darcy flow

In this paper, the Darcy model is used to describe the double diffusive flow of a fluid containing a solute. Continuous dependence of the solution on the Soret coefficient is established.  

Optimal allocation of policy limits and deductibles

In this paper, we study the problems of optimal allocation of policy limits and deductibles. Several objective functions are considered: maximizing the expected utility of wealth assuming the losses are independent, minimizing the expected total retained loss and maximizing the expected utility of wealth when the dependence structure is unknown. Orderings of the optimal allocations are obtained.  

Penalized Empirical Likelihood Estimation for Partially Linear Single Index Panel Model with Fixed Effects

This paper constructs a penalized empirical likelihood estimation method via quadratic inference function method, filter method and empirical likelihood estimation method. Under some regular conditions, we derived the large sample properties of estimators and show that the proposed empirical likelihood ratio is asymptotically to chi-square distribution. Furthermore, the infinite sample performance of the proposed method is evaluated by Monte Carlo simulation and real data analysis.  

һ�������Ȩ�͵Ľ����Լ���Ӧ��

This paper considers the asymptotics of randomly weighted sums and their maxima, where the increments {X_i,i\geq1\} is a sequence of independent, identically distributed and real-valued random variables and the weights {\theta_i,i\geq1\} form another sequence of non-negative and independent random variables, and the two sequences of random variables follow some dependence structures. When the common distribution F of the increments belongs to dominant variation class, we obtain some weakly asymptotic estimations for the tail probability of randomly weighted sums and their maxima. In particular, when the F belongs to consistent variation class, some asymptotic formulas is presented. Finally, these results are applied to the asymptotic estimation for the ruin probability.  

基于藤结构 Copula 模型的中国股市风格资产相依结构研究

首先采用AR（1）-GJR（1，1）-SkT（73，A）模型来刻画中国股市风格资产（大盘成长、大盘价值、中盘成长、中盘价值、小盘成长、小盘价值）的边缘分布，接着结合各边缘分布的残差，引入C—VineCop—ula和r）IVineCopula模型来描述这六种风格资产之间的相依结构，然后对基于CVineCopula和I）IVineCopula模型的拟合效果进行综合比较．研究结果表明：中国股市各风格资产之间的相依性存在结构性差异，最适合用I）IVineCopula模型来刻画各风格资产之间的相依结构．同类型的风格资产之间的相依程度比不同类型风格资产之间的相依程度要高；在同一类型的风格资产中，资产规模差距越大的风格资产之间的相依系数就越小．无条件的风格资产收益系列之间的相关性要显著大于有条件的风格资产收益系列之间的相关性；最后根据研究结论提出了降低风格资产组合风险的资产配置建议．  

�̶�ЧӦ�������Ե�ָ�����ģ�͵ijͷ�������Ȼ����

��This paper constructs a penalized empirical likelihood estimation method via quadratic inference function method, filter method and empirical likelihood estimation method. Under some regular conditions, we derived the large sample properties of estimators and show that the proposed empirical likelihood ratio is asymptotically to chi-square distribution. Furthermore, the infinite sample performance of the proposed method is evaluated by Monte Carlo simulation and real data analysis.