We propose a new class of extreme-value copulas which are extreme-value limits of conditional normal models. Conditional normal models are generalizations of conditional independence models, where the dependence among observed variables is modeled using one unobserved factor. Conditional on this factor, the distribution of these variables is given by the Gaussian copula. This structure allows one to build flexible and parsimonious models for data with complex dependence structures, such as data with spatial dependence or factor structure. We study the extreme-value limits of these models and show some interesting special cases of the proposed class of copulas. We develop estimation methods for the proposed models and conduct a simulation study to assess the performance of these algorithms. Finally, we apply these copula models to analyze data on monthly wind maxima and stock return minima.
翻译:我们建议了一个新的极值混合体类别,这是有条件正常模型的极端值极限。 条件性正常模型是有条件独立模型的概括化模型,在这种模型中,观测到的变量之间的依赖性使用一个未观测到的系数进行模型。根据这个系数,这些变量的分布由高西亚可观测系数提供。这个结构允许人们为具有复杂依赖性结构的数据,如具有空间依赖性或要素结构的数据,建立灵活和分散的模型。我们研究了这些模型的极端值极限,并展示了拟议中的相生体类别的一些有趣的特殊案例。我们为拟议的模型制定估算方法,并进行模拟研究以评估这些算法的性能。最后,我们运用这些可观测模型来分析每月风峰值和存量返回微型模型的数据。