Estimating conditional tail expectation with actuarial applications in view

We develop statistical inferential tools for estimating and comparing conditional tail expectation (CTE) functions, which are of considerable interest in actuarial science. In particular, we construct estimators for the CTE functions, develop the necessary asymptotic theory for the estimators, and then use the theory for constructing confidence intervals and bands for the functions. Both parametric and non-parametric approaches are explored. Simulation studies illustrate the performance of estimators in various situations. Results are obtained under minimal assumptions, and the general Vervaat process plays a crucial role in achieving these goals.     

A lower-bound oracle inequality for a blockwise-shrinkage estimate

Efromovich-Pinsker and Stein blockwise-shrinkage estimates are traditionally studied via upper-bound oracle inequalities, which bound the estimate's risk from above by the oracle's risk plus a remainder term. These bounds allow one to establish sufficient conditions for attaining the oracle's risk. To explore necessary conditions, this article develops a lower-bound oracle inequality, which bounds the estimate's risk from below by the oracle's risk minus a remainder term. In particular, the lower bound implies that thresholds must vanish for attaining the oracle's risk.     

Considerations on group-wise identical designs for linear mixed models

We consider a general class of mixed models, where the individual parameter vector is composed of a linear function of the population parameter vector plus an individual random effects vector. The linear function can vary for the different individuals. We show that the search for optimal designs for the estimation of the population parameter vector can be restricted to the class of group-wise identical designs, i.e., for each of the groups defined by the different linear functions only one individual elementary design has to be optimized. A way to apply the result to non-linear mixed models is described.     

从12SrRNA部分基因序列探讨鳄的系统发生关系

本文用常规方法测定了雅卡凯门鳄（caiman yacane）、新几内亚鳄（crocodylus novaeguineae）等2种鳄类的约400bp的mtDNA12SrRNA基因片段的部分序列，所测序列与GenBank中的其他18种鳄类的12SrRNA基因相应片段同源序列一起经Clustal X1．8软件进行比对，并以乌龟（chinemys reevesii）为外群，用ClustalX（1．8），Mega2软件以及paup软件将这20种鳄的12SrRNA基因部分序列进行比对后构建了20种鳄的进化关系树，并分别用NJ树，MP树探讨它们之间的系统发生关系。其结果显示：食鱼鳄属Gavialis与马来假食鱼鳄属Tomistoma的亲缘关系较近，构成姐妹群并位于鳄科分支的基部。非洲窄吻鳄（Crocodylus cataphractus）与骨喉鳄（Osteolaemus retraspis）形成姐妹群，它们的亲缘关系比与其它真鳄类的关系更近，赞同非洲窄吻鳄应从鳄属中独土出来归属于长吻鳄属Mecistops的观点，因此鳄科包括鳄属、骨喉鳄属和长吻鳄属，它们的关系为（鳄属（骨喉鳄属，长吻鳄属））。鼍科4属中凯门鳄属与黑鳄属关系最近，接下来的是古鳄属、鼍属，而且鼍属是鼍科中起源最早的类群。扬予鳄（Alligator sinensis）与密河鳄（Alligator mississippiensis）较近的亲缘关系得到支持，但它们并没有形成姐妹群关系。     

Bayesian mixture modeling for spatial Poisson process intensities,with applications to extreme value analysis

We propose a method for the analysis of a spatial point pattern, which is assumed to arise as a set of observations from a spatial nonhomogeneous Poisson process. The spatial point pattern is observed in a bounded region, which, for most applications, is taken to be a rectangle in the space where the process is defined. The method is based on modeling a density function, defined on this bounded region, that is directly related with the intensity function of the Poisson process. We develop a flexible nonparametric mixture model for this density using a bivariate Beta distribution for the mixture kernel and a Dirichlet process prior for the mixing distribution. Using posterior simulation methods, we obtain full inference for the intensity function and any other functional of the process that might be of interest. We discuss applications to problems where inference for clustering in the spatial point pattern is of interest. Moreover, we consider applications of the methodology to extreme value analysis problems. We illustrate the modeling approach with three previously published data sets. Two of the data sets are from forestry and consist of locations of trees. The third data set consists of extremes from the Dow Jones index over a period of 1303 days.     

On characterizations of the logistic distribution

We modify and extend George and Mudholkar's [1981. A characterization of the logistic distribution by a sample median. Ann. Inst. Statist. Math. 33, 125–129] characterization result about the logistic distribution, which is in terms of the sample median and Laplace distribution. Moreover, we give some new characterization results in terms of the smallest order statistics and the exponential distribution.     

REPATRIATION OF DEBT IN THE EURO CRISIS

With the beginning of the Euro Crisis, the long‐standing trend of European financial integration reversed. Investors unwound cross‐border positions of debt obligations and increased holdings of locally issued debt. In other words, debt obligations were repatriated. We use data on bank portfolios to document three new empirical regularities of the financial disintegration: (i) repatriation affected mainly debt of crisis countries; (ii) repatriation affected mainly public debt; (iii) the public debt of crisis countries that was not repatriated was reallocated to large and politically influential countries within the Euro area. We read these results in light of standard theories of cross‐border portfolio allocation and argue that the sum of these patterns constitutes evidence for the secondary market theory of public debt.     

政府部门间G2G信息资源共享的演化博弈分析

简要介绍了电子政务的发展和演化博弈理论,将政府部门置于一个不断渐进地演化系统中,根据演化博弈系统构建出演化博弈模型和演化相位图,探究及分析政府部门所拥有的信息资源、信息资源共享的收益系数、政府部门的风险系数和信息资源共享中的技术成本等相关参数对政府部门之间的信息资源共享所产生的影响,并据此提出一些有针对性的建议,为提升跨政府部门之间信息资源共享能力和电子政府信息服务能力提供科学的理论支持。     

Understanding sex: the right to legal capacity to consent to sex

This article addresses the right to legal capacity to consent to sex of people with intellectual disabilities. Article 12 of the Convention on the Rights of Persons with Disabilities guarantees the right to legal capacity on an equal basis in all areas of life. This article discusses sex as an area of life in which people with intellectual disabilities are frequently not being granted legal capacity on an equal basis. The article examines current capacity to consent to sex law in Ireland, England and Wales in light of Article 12. It proposes an ‘agreement model’ as a potential alternative that would be Article 12 compliant.     

Adaptive wavelet estimation of a density from mixtures under multiplicative censoring

In this paper, a mixture model under multiplicative censoring is considered. We investigate the estimation of a component of the mixture (a density) from the observations. A new adaptive estimator based on wavelets and a hard thresholding rule is constructed for this problem. Under mild assumptions on the model, we study its asymptotic properties by determining an upper bound of the mean integrated squared error over a wide range of Besov balls. We prove that the obtained upper bound is sharp.