最优分红策略:正则与脉冲混合控制问题

本文对扩散模型下的最优分红问题作了进一步分析.注意到,累积分红量是一个关于时间的右连左极过程,它的路径由连续和跳跃两部分组成.因此,本文在建模中同时加入了连续分红和脉冲分红两种形式,这就构成了一个正则和脉冲分红混合的最优控制问题.假设所有分红量存在一个比例成本,对于每次的脉冲分红量存在一个固定成本.此外,对于连续分红部分,假设存在一个有限的最大分红率.用漂移Brown运动描述公司的盈余过程,优化目标设定为最大化公司破产前分红现值的期望值,本文给出了值函数以及最优分红策略的解析表达式.结论表明,最优的分红策略为阀值(threshold)策略和脉冲策略的组合形式.     

一类混合分红策略下的广义Erlang(n)风险模型

本文考虑混合分红策略下索赔来到间隔为广义Erlang(n)分布的更新风险模型,利用指数分布的无记忆性,分别得到破产前期望折现分红函数和折现分红的矩母函数满足的积分-微分方程及其边界条件.最后给出索赔为指数分布及索赔来到间隔为广义Erlang(2)分布的风险模型的期望折现分红函数的精确表达式.     

具有混合指数索赔分布的经典复合泊松风险模型中的分红问题

本文研究了具有某混合指数索赔分布的经典复合泊松风险模型中的分红问题.利用随机控制理论,在无界分红强度的假设下,给出了值函数的显式表达式和相应的最优分红策略.推广了文献[4]的结果.     

带相关风险的保险公司的最优分红和再保险问题

本文的研究对象是带两种相关风险业务的保险公司.本文用复合Poisson过程描述这两种风险;应用扩散逼近理论,建立了一个扩散逼近模型.利用动态再保险策略,公司可以降低其破产概率,同时通过给客户分红,公司可以保持竞争力.公司的目标是寻找最优策略和值函数来最大化期望折现分红.因为超额损失再保险策略优于比例再保险策略,所以,本文考虑公司的超额损失再保险及其分红问题.问题分两种情形讨论:分红率有界和分红率无界.在这两种情形下,本文最终得到了值函数和相应最优策略的具体表达式.     

具有混合指数索赔分布的经典复合泊松风险模型中的分红问题（英文）

本文研究了具有某混合指数索赔分布的经典复合泊松风险模型中的分红问题.利用随机控制理论,在无界分红强度的假设下,给出了值函数的显式表达式和相应的最优分红策略.推广了文献[4]的结果.     

复合Poisson模型带投资-借贷利率和固定交易费用的最优分红策略

本文研究了复合Poisson模型带投资-借贷利率和固定交易费用的最优分红问题。通过控制分红时刻和分红量，最大化直到绝对破产时刻的累积期望折现分红。由于考虑固定交易费用，问题为一个随机脉冲控制问题。首先，本文给出了一个策略是平稳马氏策略的充分必要条件。借助于测度值生成元理论得到测度值动态规划方程(简称测度值DPE),并且在没有任何附加条件下证明了验证定理。通过Lebesgue分解，本文讨论了测度值DPE和拟变分不等式(简称QVI)之间的关系，证明了最优分红策略为具有波段结构的平稳马氏策略。最后，本文给出了求解n-波段策略和相应值函数的算法。当索赔额服从指数分布时，得到了值函数的显示解和最优分红策略。     

非时齐复合泊松过程下对偶风险模型的破产特征量研究

将经典的对偶风险模型中的收益到达过程推广为非时齐的泊松过程.运用经典方法和时变方法,计算了该模型下的破产概率,并定义了时变后相应模型的广义期望折罚函数,验证了时变方法对非时齐泊松风险模型的有效性,最后又考虑了该模型在带壁分红策略下的情形,当单次索赔额服从指数分布时,得到了它的期望折罚函数以及期望折现分红函数.     

相依的Erlang(2)风险模型下的多段分红问题（英文）

本文用相依的Erlang(2)风险模型模拟了保险公司的盈余过程,讨论了该模型在多段分红策略下的若干问题.首先,期望折扣罚金函数所满足的分段的积分微分方程被给出.然后应用该结果,得出了其所满足的瑕疵更新方程并给出了当索赔时间间隔和索赔额的联合分布为有理分布时该方程的解.本文的结论深化了精算学中一些已有研究成果.     

基于交替更新过程的模糊随机破产模型

假设索赔额、盈余额和更新过程均是在模糊随机环境中,并且将索赔过程定义为在交替更新过程.当索赔额和时间间隔是服从不同的指数分布时,本文建立了交替更新过程下的模糊随机破产模型,并给出了最终破产概率公式与最终破产机会均值公式.     

经典风险模型最优分红值的估计方法

本文考虑经典风险模型在障碍分红策略下的最优分红值的估计问题.当个体索赔额是混合指数分布时,给出最优分红值的解析表达式.但当个体索赔额是一般分布时,最优分红值的解析表达式往往不能得到,这时我们提供了两种估计方法,一是Lundberg渐近估计法,二是离散化模型估计法.最后给出几个数值例子,对不同计算方法下的估计值作出比较.     

The expected discounted penalty function for the perturbed compound Poisson risk process with constant interest

In this paper, we consider the Gerber-Shiu expected discounted penalty function for the perturbed compound Poisson risk process with constant force of interest. We decompose the Gerber-Shiu function into two parts: the expected discounted penalty at ruin that is caused by a claim and the expected discounted penalty at ruin due to oscillation. We derive the integral equations and the integro-differential equations for them. By solving the integro-differential equations we get some closed form expressions for the expected discounted penalty functions under certain assumptions.     

具有常数红利边界的两类索赔相关风险模型数

研究常数红利边界下两类索赔相关的风险模型,两类索赔计数过程分别为独立的Poisson过程和广义Erlang(2)过程.利用分解Gerber-Shiu函数的方法,得到了Gerber-Shiu函数满足的积分-微分方程、边界条件、解析表达式及两类索赔额均服从指数分布时的破产概率表达式.     

Constant dividend barrier in a risk model with interclaim-dependent claim sizes

The risk model with interclaim-dependent claim sizes proposed by Boudreault et al. [Boudreault, M., Cossette, H., Landriault, D., Marceau, E., 2006. On a risk model with dependence between interclaim arrivals and claim sizes. Scand. Actur. J., 265-285] is studied in the presence of a constant dividend barrier. An integro-differential equation for some Gerber-Shiu discounted penalty functions is derived. We show that its solution can be expressed as the solution to the Gerber-Shiu discounted penalty function in the same risk model with the absence of a barrier and a combination of two linearly independent solutions to the associated homogeneous integro-differential equation. Finally, we analyze the expected present value of dividend payments before ruin in the same class of risk models. An homogeneous integro-differential equation is derived and then solved. Its solution can be expressed as a different combination of the two fundamental solutions to the homogeneous integro-differential equation associated to the Gerber-Shiu discounted penalty function.     

On a compound Poisson risk model with delayed claims and random incomes

The main focus of this paper is to analyze the Gerber-Shiu penalty function of a compound Poisson risk model with delayed claims and random incomes. It is assumed that every main claim will produce a by-claim which can be delayed with a certain probability. We derive the integral equation satisfied by the Gerber-Shiu penalty function. Given that the premium size is exponentially distributed, the explicit expression for the Laplace transform of the Gerber-Shiu penalty function is derived. Finally, when the premium sizes have rational Laplace transforms, we also obtain the Laplace transform of the Gerber-Shiu penalty function.     

On the expected discounted penalty functions for two classes of risk processes under a threshold dividend strategy

In this paper, the discounted penalty (Gerber-Shiu) functions for a risk model involving two independent classes of insurance risks under a threshold dividend strategy are developed. We also assume that the two claim number processes are independent Poisson and generalized Erlang (2) processes, respectively. When the surplus is above this threshold level, dividends are paid at a constant rate that does not exceed the premium rate. Two systems of integro-differential equations for discounted penalty functions are derived, based on whether the surplus is above this threshold level. Laplace transformations of the discounted penalty functions when the surplus is below the threshold level are obtained. And we also derive a system of renewal equations satisfied by the discounted penalty function with initial surplus above the threshold strategy via the Dickson-Hipp operator. Finally, analytical solutions of the two systems of integro-differential equations are presented.     

马氏调制费率的带干扰风险模型

考虑了一类具有马氏调制的带干扰连续时间风险模型,得到了该模型下其条件Gerber-Shiu折现罚金函数所满足的积分方程,Laplace变换及渐近解.在两状态情形下,当索赔额的分布为有理数情况时得到了条件Gerber-Shiu折现罚金函数的具体表达式并给出了数值例子     

A generalized penalty function with the maximum surplus prior to ruin in a MAP risk model

In this paper, a risk model where claims arrive according to a Markovian arrival process (MAP) is considered. A generalization of the well-known Gerber-Shiu function is proposed by incorporating the maximum surplus level before ruin into the penalty function. For this wider class of penalty functions, we show that the generalized Gerber-Shiu function can be expressed in terms of the original Gerber-Shiu function (see e.g. [Gerber, Hans U., Shiu, Elias, S.W., 1998. On the time value of ruin. North American Actuarial Journal 2(1), 48-72]) and the Laplace transform of a first passage time which are both readily available. The generalized Gerber-Shiu function is also shown to be closely related to the original Gerber-Shiu function in the same MAP risk model subject to a dividend barrier strategy. The simplest case of a MAP risk model, namely the classical compound Poisson risk model, will be studied in more detail. In particular, the discounted joint density of the surplus prior to ruin, the deficit at ruin and the maximum surplus before ruin is obtained through analytic Laplace transform inversion of a specific generalized Gerber-Shiu function. Numerical illustrations are then examined.     

The Gerber-Shiu discounted penalty function in the risk process with phase-type interclaim times

In this paper, we consider the Gerber-Shiu discounted penalty function for the Sparre Anderson risk process in which the interclaim times have a phase-type distribution. By the Markov property of a joint process composed of the risk process and the underlying Markov process, we provide a new approach to prove the systems of integro-differential equations for the Gerber-Shiu functions. Closed form expressions for the Gerber-Shiu functions are obtained when the claim amount distribution is from the rational family. Finally we compute several numerical examples intended to illustrate the main results.     

On a risk model with stochastic premiums income and dependence between income and loss

Labbé and Sendova (2009) [9] consider a compound Poisson risk model with stochastic premiums income. In this paper, we extend their model by assuming that there exists a specific dependence structure among the claim sizes, interclaim times and premium sizes. Assume that the distributions of the premium sizes and interclaim times are controlled by the claim sizes. When the individual premium sizes are exponentially distributed, the Laplace transforms and defective renewal equations for the (Gerber-Shiu) discounted penalty functions are obtained. When the individual premium sizes have rational Laplace transforms, we show that the Laplace transforms for the discounted penalty functions can also be obtained.     

On the Gerber-Shiu discounted penalty function for a surplus process described by PDMPs

In this paper, we investigate the Gerber-Shiu discounted penalty function for the surplus process described by a piecewise deterministic Markov process （PDMP）. We derive an integral equation for the Gerber-Shiu discounted penalty function, and obtain the exact solution when the initial surplus is zero. Dickson formulae are also generalized to the present surplus process.