Asymptotics for ruin probability of some negatively dependent risk models with a constant interest rate and dominatedly-varying-tailed claims

This paper deals with some negatively dependent risk models with a constant interest rate, dominatedly-varying-tailed claims and a general premium process. We first establish two weak asymptotic equivalent formulae for the finite-time ruin probabilities. Furthermore, we obtain a uniform result for the dependent renewal risk model with a constant premium rate.     

基于具有LR型模糊输出回归模型的保费预测

在保费预测研究中,提出了一种基于模糊回归模型的预测方法.采用模糊最小二乘法,针对清晰输入和LR型模糊输出,在考虑输出量隶属函数类型存在差异问题基础之上,得到模型回归系数的迭代解.通过最小二乘估计的定性分析,给出检验模型拟合度的指标.结合保费数据的预测结果表明模型可行且具有较强的解释能力.     

Multi-year non-life insurance risk of dependent lines of business in the multivariate additive loss reserving model

We derive analytical estimators of non-life insurance risk in multi-year view for the multivariate additive loss reserving model. Thereby we jointly assess reserve and premium risks of multiple years for portfolios of possibly dependent lines of business in one integrated approach. By extending existing formulae for the univariate additive model to the multivariate case, risk estimators for the aggregated portfolio now include the inherent dependencies among all lines of business. The resulting risk evaluation over one-year and general multi-year horizons is fundamental to regulatory reporting (e.g. the ORSA process in Solvency II) and risk-based business planning of non-life insurers with multiple lines of business. A case study illustrates the fruitful application of our formulae and reproduces previous findings for the special case of ultimo view.     

On a risk model with random incomes and dependence between claim sizes and claim intervals

In this paper, we construct a risk model with a dependence setting where there exists a specific structure among the time between two claim occurrences, premium sizes and claim sizes. Given that the premium size is exponentially distributed, both the Laplace transforms and defective renewal equations for the expected discounted penalty functions are obtained. Exact representations for the solutions of the defective renewal equations are derived through an associated compound geometric distribution. When the claims are subexponentially distributed, the asymptotic formulae for ruin probabilities are obtained. Finally, when the individual premium sizes have rational Laplace transforms, the Laplace transforms for the expected discounted penalty functions are obtained.     

分数跳-扩散环境下几种新型期权定价模型

假定股票价格遵循分数跳-扩散过程,利用公平保费原则和价格过程的实际测度,获得几种新型期权——欧式看涨幂期权、欧式上封顶及下保底看涨幂期权定价公式.对期权定价模型进行了推广.     

A gamma-minimax result in credibility theory

The statistical decision problem of experience ratemaking has been described by Bühlmann (1975) as a two-person game of the actuary (player 2) against (malevolent) nature (player 1). Within this framework premium calculation procedures are strategies of player 2 and some types of credibility formulae can be regarded as Bayesian strategies or in terms of statistical decision theory as (linear) Bayes estimators. Since the application of the Bayes principle of game theory to insurance ratemaking is not appropriate — usually the actuary has not enough information for identifying one single prior — it is quite natural to select a premium calculation procedure which is optimal according to the minimax principle of game theory or according to the so-called gamma-minimax principle. This principle is more adaptable than the minimax principle since it allows to take into account vague prior information. In this paper credibility formulae are derived which are gamma-minimax for special types of prior information similar to those in Bühlmann's paper.     

PA-α模型下异质的养老保险投资组合的研究

首先对文献[1]中在PA-α模型下有关保险费及收益的上下界的结论做了改进,其次给出了一种实际保费的加权计算公式,并给出实际例子说明了所得结果;最后本文讨论了PA-α模型中α未知的情况下,生存给付S=0,保险费Π给定,保险公司及投保人对死亡给付D的希望取值,并给出D的上下界的计算公式.     

Mathematical analysis of the two-color partial rainbow options

In this article, two-color partial rainbow options (TCPROs) are proposed. Such options allow holders to choose between the two underlying vanilla options at a specified time before expiry. Examples of benefits of TCPROs to both holders and issuers are given. Pricing formulae for such options are derived. The extra premium due to the choosing feature of a TCPRO, called the price of choice, is a nonnegative decreasing function of the correlation coefficient of the two underlying assets and the remaining time to choose. Numerical results are obtained to show that while TCPROs are more valuable than the underlying vanilla options, their risk parameters such as delta and gamma are smaller.     

On convex principles of premium calculation

The classical definition of a principle of premium calculation is generalized: risks with identical distributions do not necessarily lead to the same premium. In the first part (Sections 1–3) the theoretical properties of convexity are discussed; in particular, the gradient of a principle is introduced. It is noted that the more common principles are all convex. In the second part these notions are applied to solve two problems under rather general assumptions: (1) Optimal purchase of reinsurance: If the first insurer knows how the reinsurer determines his premium, what form and degree of reinsurance should he choose? (2) Optimal cooperation: How should n companies split up a given risk to minimize the total premium? The case where the optimal decompostion consists of constant quotas is described in detail. In general, there is a close connection with Pareto optimality on the one hand, and no trade equilibria on the other.     

Summation formulae involving the Laguerre polynomial

A general result involving the generalized hypergeometric function is deduced by the elementary manipulation of series. Kummer's first theorem for the confluent hypergeometric function and two summation formulae for the Gauss hypergeometric function are then applied and new summation formulae involving the Laguerre polynomial are deduced.     

广义负相依一般风险模型中有限时破产概率的估计及数值模拟

本文研究了一类带利率的重尾相依风险模型, 其中索赔额是一列上广义负相依随机变量, 索赔到达过程是一般的非负整值过程, 并且独立于索赔额序列, 保费收入过程是一个一般的非负非降随机过程. 我们考虑了两种情况, 其一是索赔额、索赔到达过程及保费收入过程相互独立, 其二是累积折现保费收入总量的尾概率可以被索赔额的尾概率高阶控制, 得到了保险公司有限时破产概率的渐近估计,并且给出了相应的数值模拟, 验证了理论结果的合理性.     

一个特殊可重复排列数的算法

研究一类特殊的可重复排列性质,建立了一般情形下求这类排列数的递推公式,导出了一些特殊情形下的具体计算公式.     

Risk measures, distortion parameters, and their empirical estimation

Risk measures are of considerable current interest. Among other uses, they allow an insurer to calculate a risk-loaded premium for a random loss. However, the premium principle in use by the insurer may be, at least in part, based on considerations other than risk. It is then important to quantify the degree to which the premium compensates the insurer for the risk associated with the loss. This can be done by choosing a suitable risk measure and solving for the parameter that leads to the insurer’s premium. When the loss distribution is unknown, this becomes a statistical estimation problem.In this paper, we investigate the nonparametric estimation of the parameter associated with a distortion-based risk measure. It is assumed that the premium principle is known, but no information is assumed about the loss distribution, and therefore empirical estimators are used. We explore the asymptotic properties of the resulting estimator of the risk measure parameter in general and for three well-known risk measures in particular: the proportional hazards transform, the Wang transform, and the conditional tail expectation.     

A generalized penalty function in Sparre Andersen risk models with surplus-dependent premium

In a general Sparre Andersen risk model with surplus-dependent premium income, the generalization of Gerber-Shiu function proposed by Cheung et al. (2010a) is studied. A general expression for such Gerber-Shiu function is derived, and it is shown that its determination reduces to the evaluation of a transition function which is independent of the penalty function. Properties of and explicit expressions for such a transition function are derived when the surplus process is subject to (i) constant premium; (ii) a threshold dividend strategy; or (iii) credit interest. Extension of the approach is discussed for an absolute ruin model with debit interest.     

The uncertain premium principle based on the distortion function

In this paper, we discuss the premium principle in uncertain environment. First, the net premium principle for uncertain risks is presented within the framework of uncertainty theory. With the help of distortion function, a new uncertain premium principle is derived from the uncertain net premium. Some properties of uncertain distortion premium principle are proved. Furthermore, a sufficient and necessary condition that an uncertain premium principle is an uncertain distortion premium principle has been characterized. Finally, some examples are given to illustrate the calculations of the uncertain distortion premium.     

On general Hermite trigonometric interpolation

Summary A sequence of general Hermite trigonometric interpolation polynomials with equidistant interpolation points is given. Integrating these interpolation formulae a sequence of quadrature formulae for the integration of periodic functions is obtained. Derivative-free remainders are stated for these interpolation and quadrature formulae.This work was done at the Max-Planck-Institut für Physik und Astrophysik, München.     

Asymptotic expansions of the binomial coefficients

A general formulae for the asymptotic expansion of not centered binomial coefficients are derived and some useful estimates of the binomial coefficients are presented. The sum of the binomial coefficients is also studied.     

Simple Fourth-Degree Cubature Formulae with Few Nodes over General Product Regions

A simple method is proposed for constructing fourth-degree cubature formulae over general product regions with no symmetric assumptions. The cubature formulae that are constructed contain at most $n^2+7n+3$ nodes and they are likely the first kind of fourth-degree cubature formulae with roughly $n^2$ nodes for non-symmetric integrations. Moreover, two special cases are given to reduce the number of nodes further. A theoretical upper bound for minimal number of cubature nodes is also obtained.     

认股权证的修正精算定价研究

基于修正Bladt和Rydberg在无市场假设下关于期权定价的保险精算方法的基础上,从评估实际损失和相应概率分布角度,利用公平保费原则建立认股权证的定价模型,并给出定价公式.且当投资者对原生资产期望回报率为无风险利率时,该定价为风险中性价格.     

A note on the Flesaker-Hughston model of the term structure of interest rates

A term structure model proposed by Flesaker and Hughston (1996a,b) is analysed within the general framework of arbitrage-free term structure modelling. Basic valuation formulae for caps and swaptions are presented.