企业年金中的委托-代理风险研究

企业年金涉及雇员、雇主、账户管理人、投资管理人等多方的利益。文章分析了在不同的管理模式下,企业年金各方所形成的双层委托-代理关系,剖析了企业年金委托-代理风险形成的原因,在此基础之上,提出了应对企业年金委托-代理风险的对策。     

“做实做小”个人账户对个人养老金水平的影响

 本文引入养老保险金记账利率和工资增长率，测算了在不同初始缴费工资和缴费年限条件下实施“做实做小”个人账户政策对参保人养老金水平的影响。通过分析得出：1.政策调整后，养老金给付结构较调整前更能体现缴费积累与养老金水平的内在经济联系； 2.政策调整后个人养老金水平普遍不如政策调整前的水平，政策调整后养老金水平高于政策调整前均出现在缴费年限较长以及初始缴费工资较高的情况下；3.政策调整对不同的参保人影响不同。政策调整加大了低初始缴费工资人群的生活压力；拉大了男、女职工退休养老金的差距，不利于当前社会男女平等和贫富分化问题的解决。     

从saragur到salr——撒拉族源流的语言人类学研究

本文以撒拉族相关族名为重点,通过语言人类学的研究,提出撒拉族源自Qaramang(尕勒莽)部,和土库曼、土耳其的Karaman,乌兹别克的努尔塔Salur人都应是源自历史上著名的、Salur乌古斯部的一位领袖Karaman的观点。撒拉族的自称Salr,是由历史上的Salur、Salgur、*Saragur、*Sarg Ogur等演变而来。Sarg Ogur意为黄箭(部落),曾是匈奴的一个重要组成部分。撒拉族等一些乌古斯(Ouz)民族和维吾尔族、裕固族的祖先回纥(Ogur)都同出一源。     

用跳马步系列研究奇素数阶规则完美幻方的个数

本文先介绍跳马步系列的有关概念及性质,然后用跳马步系列研究奇素数阶规则完美幻 方的个数。     

精算思想的演进与精算理论发展综述

精算是保险发展的基础,是保险经营的技术支持。精算在国外有四百年的发展历史,引入中国只有二十年。要使精算技术在中国得到发展创新并为社会需要服务,必须了解精算思想产生的历史背景,厘清精算理论发展的脉络,真正把握精算思想的实质。基于此,介绍了精算各发展时期的主要代表人物及其学术思想,阐述精算技术对各时期保险发展的影响,同时对精算学与复利理论、数学、统计学、计算技术、金融经济学交叉融合的历史过程进行了分析述评。     

Variance bounds for estimators in autoregressive models with constraints

We consider nonlinear and heteroscedastic autoregressive models whose residuals are martingale increments with conditional distributions that fulfil certain constraints. We treat two classes of constraints: residuals depending on the past through some function of the past observations only, and residuals that are invariant under some finite group of transformations. We determine the efficient influence function for estimators of the autoregressive parameter in such models, calculate variance bounds, discuss information gains, and suggest how to construct efficient estimators. Without constraints, efficient estimators can be given by weighted least squares estimators. With the constraints considered here, efficient estimators are obtained differently, as one-step improvements of some initial estimator, similarly as in autoregressive models with independent increments.     

Performance of the One-Sample Goodness-of-Fit P–P-Plot Length Test

This article studies the performance of the one-sample goodness-of-fit test which is based on the length of the P–P-plot initially introduced in a similar context by Reschenhofer and Bomze (1991 Reschenhofer , E. , Bomze , I. M. ( 1991 ). Length tests for goodness-of-fit . Biometrika 78 : 207 – 216 . [Google Scholar]). The distributional properties of the length test are revised empirically via simulations. In the Monte Carlo power study that follows the length test is shown empirically to have high power under various alternatives considered relative to members of the Cramér–von Mises family of goodness-of-fit tests, and the Kolmogorov–Smirnov test.     

Four Correlation Coefficients with a Third Blocking Variable: Their Efficacy,Relative Efficiency,and Test Statistics

Abstract

The efficacy and the asymptotic relative efficiency (ARE) of a weighted sum of Kendall's taus, a weighted sum of Spearman's rhos, a weighted sum of Pearson's r's, and a weighted sum of z-transformation of the Fisher–Yates correlation coefficients, in the presence of a blocking variable, are discussed. The method of selecting the weighting constants that maximize the efficacy of these four correlation coefficients is proposed. The estimate, test statistics and confidence interval of the four correlation coefficients with weights are also developed. To compare the small-sample properties of the four tests, a simulation study is performed. The theoretical and simulated results all prefer the weighted sum of the Pearson correlation coefficients with the optimal weights, as well as the weighted sum of z-transformation of the Fisher–Yates correlation coefficients with the optimal weights.     

Approximating M/G/1 Waiting Time Tail Probabilities

Abstract

We propose a new approximation formula for the waiting time tail probability of the M/G/1 queue with FIFO discipline and unlimited waiting space. The aim is to address the difficulty of obtaining good estimates when the tail probability has non-exponential asymptotics. We show that the waiting time tail probability can be expressed in terms of the waiting time tail probability of a notional M/G/1 queue with truncated service time distribution plus the tail probability of an extreme order statistic. The Cramér–Lundberg approximation is applied to approximate the tail probability of the notional queue. In essence, our technique extends the applicability of the Cramér–Lundberg approximation to cases where the standard Lundberg condition does not hold. We propose a simple moment-based technique for estimating the parameters of the approximation; numerical results demonstrate that our approximation can yield very good estimates over the whole range of the argument.