保单个数为Poisson分布的总理赔额分布函数的界值研究

根据单个保单理赔额分布函数F(z)的一些特殊性质,研究了开放个别风险模型在保单个数N为Poisson分布下,总理赔额分布函数F_S(x)对任意x(x≥0)的界值问题,得到一些实用的、便于数值计算的界值结果,具有重要的应用价值．     

保险公司赔付及破产的随机模拟与分析

孙立娟、顾岚等．保险公司赔付及破产的随机模拟与分析．本文研究定期人寿保险的承保理赔及破产模型,其中保单到达和索赔出现服从相互独立的Ｐｏｉｓｏｎ过程。对此模型给出了破产概率的一个具体上界,通过随机模拟生成了持有保单数和理赔过程的样本轨道,分析研究破产概率与准备金和理赔额之间的关系     

随机利率下的增额寿险模型研究

在实际的保险精算中,保单保险金现值函数的期望就是该种保单的纯保费,而方差常用来度量该种保单的风险.对随机利率采用W iener过程建模,得到了增额寿险保险金现值函数的期望和方差.     

基于 HNBUE(HNWUE) 寿命分布类的M/G/1排队等待时间分布函数的指数型界值

本文考虑一个M/G/1排队,其中顾客到达率为λ(0)和服务时间分布函数为G(t).在顾客服务时间的分布函数G(t)具有HNBUE(HNWUE)分布类特性的条件下,本文研究等待时间分布函数的界值问题,得到等待时间分布函数的易于计算的、有实用价值的指数型界值表达式,并通过计算例子表明所得结果有应用价值.     

阈红利边界下理赔时间间隔与理赔额相依的风险模型

考虑阈红利边界下理赌时间间隔与理赔额相依的风险模型.首先给出了该模型的Gerber- Shiu函数满足的积分.微分方程及更新方程,然后利用Laplace变换及复合几何分布函数得到了Gerber-Shiu函数的确切表达式.     

更新风险模型中破产概率的一个局部结果

进一步研究延迟更新风险模型,在假定个体索赔额是重尾分布的前提下得到了破产概率的一个局部等价式R(x,x z]～z/ρμ^-F(x),其中F表示索赔额的分布函数,μ为其均值,ρ表示模型的安全负荷系数,极限过程是x→∞．并且对Sparre Anderson模型作了推广,得到了相应的结果．     

保费收入服从泊松过程的一类相依更新风险模型研究

本文研究了保费收入过程是泊松过程和聚合理赔过程中理赔间隔时间和个别理赔额之间具有Boudreault et al.(2006)中所描述的相依结构的一类更新风险模型.运用生成函数、离散形式的Dickson-Hipp算子和反Z变换等一系列方法,推导出了该模型的Gerber-Shiu函数的生成函数的精确表达式,以及它所满足的瑕疵更新方程.     

变保费率Cox风险模型的研究

研究了当保费率随理赔强度的变化而变化时C ox风险模型的折现罚金函数,利用后向差分法得到了折现罚金函数所满足的积分方程,进而得到了破产概率,破产前瞬时盈余、破产时赤字的各阶矩所满足的积分方程.最后给出当理赔额服从指数分布,理赔强度为两状态的马氏过程时破产概率的拉普拉斯变换,对一些具体数值计算出了破产概率的表达式.     

双险种最优再保险策略

本文对双险种风险模型,在一险种采取比例再保险,另一险种采取超出损失再保险策略下,得到调节系数与再保险自留水平之间的函数关系式,在理赔额为指数分布和Erlang(2)分布的条件下,得到最优比例再保险和超出损失再保险的自留水平,以及调节系数最大值。     

风险非同质性保单组合赔付额的计算

对于保单组合赔付次数及赔付额的计算,是非寿险精算研究的一项基本内容.讨论了非同质风险下的保单组合,在赔付次数采用混合泊松分布拟合时的两种情况下赔付额分布的计算,给出了相应的迭代公式.     

Stochastic comparison of aggregate claim amounts between two heterogeneous portfolios and its applications

The aggregate claim amount in a particular time period is a quantity of fundamental importance for proper management of an insurance company and also for pricing of insurance coverages. In this paper, we show that the proportional hazard rates (PHR) model, which includes some well-known distributions such as exponential, Weibull and Pareto distributions, can be used as the aggregate claim amount distribution. We also present some conditions for the use of exponentiated Weibull distribution as the claim amount distribution. The results established here complete and extend the well-known result of Khaledi and Ahmadi (2008).     

On variational bounds in the compound Poisson approximation of the individual risk model

We present new upper bounds for the total variation distance between the aggregate claims distribution in the individual risk model and a suitable compound Poisson distribution. It turns out that the bounds are generally valid and contain so-called magic factors. Higher-order approximations, including the signed Kornya–Presman measures, are also investigated. In contrast to results of a previous paper by the author, the results do not depend on a joint decomposition of the individual claim amount distributions. Further, we do not need to assume the finiteness of moments.     

How retention levels influence the variability of the total risk under reinsurance

Recently, Escudero and Ortega (Insur. Math. Econ. 43:255–262, 2008) have considered an extension of the largest claims reinsurance with arbitrary random retention levels. They have analyzed the effect of some dependencies on the Laplace transform of the retained total claim amount. In this note, we study how dependencies influence the variability of the retained and the reinsured total claim amount, under excess-loss and stop-loss reinsurance policies, with stochastic retention levels. Stochastic directional convexity properties, variability orderings, and bounds for the retained and the reinsured total risk are given. Some examples on the calculation of bounds for stop-loss premiums (i.e., the expected value of the reinsured total risk under this treaty) and for net premiums for the cedent company under excess-loss, and complementary results on convex comparisons of discounted values of benefits for the insurer from a portfolio with risks having random policy limits (deductibles) are derived.      

Bounds for the optimal critical claim size of a bonus system

The optimal critical claim size of a bonus system determines whether to file a claim with the insurance company after having an accident. The aim of this paper is to demonstrate, within the framework of a simple model, how bounds for the optimal critical claim size can be constructed when only incomplete information on the claim amount distribution is available.     

Application of the problem of moments to derive bounds on integrals with integral constraints

Recently a lot of results (for a review see Goovaerts et al. (1983)) have been obtained for bounds on stop-loss premiums in case of incomplete information on the claim distribution.As a consequence some extremal distributions (depending on the retention limit) have been characterized. The extremal distributions for the stop-loss ordering in case of fixed values of the retention limit are obtained by means of deep results from the theory of convex analysis. In the present contribution it is shown, by means of some results from the problem of moments, how bounds on integrals with integral constraints can be obtained. We assume only the knowledge of the moments μ₀, μ₁, …, μ_n.     

Asymptotics for tail probability of total claim amount with negatively dependent claim sizes and its applications

In this paper, we obtain the asymptotics for the tail probability of the total claim amount with negatively dependent claim sizes in two cases: in the first case, the distribution tail of the claim number is dominatedly varying; in the second case, the distribution of the claim number is in the maximum domain of attraction of the Gumbel distribution, and the claim sizes are light-tailed. In both cases, we assume that the claim sizes are nondegenerate negatively dependent and identically distributed random variables and that the claim number is not necessarily independent of the claim sizes. As applications, we derive asymptotics for the finite-time ruin probabilities in some dependent compound renewal risk models with constant interest rate.     

Lower and upper bounds of large deviation for sums of subexponential claims in a multi-risk model

In view of the actual condition of the insurance company, a multi-risk model is proposed. The lower and upper bounds for the sums of subexponential claims in this model are given. The proof method is based on the results of the total claim amount under subexponential class.     

负二项分布的优良特性及其在风险管理中的应用

孟生旺．负二项分布的优良特性及其在风险管理中的应用．数理统计与管理，１９９８，１７（２），９～１２．负二项分布之所以在风险管理中被广泛应用是由其优良特性所决定的。本文主要讨论了其中三个方面的问题：第一，负二项分布在描述风险集体中任意风险的索赔次数时表现为伽玛分布对泊松分布按参数变化的加权平均；第二，负二项分布在描述某些风险的累积索赔额时具有复合泊松分布的形式；第三，负二项分布是当风险的索赔频率强度之间存在正向传染时索赔次数的分布