保费收入随机化条件下的保险公司破产概率模型研究

保费收入是保险公司破产概率的重要影响因素。传统的保险公司破产概率模型常将保费收入过程看作连续的确定性过程,然而在现实中,保费收入过程却是一个离散的随机过程。本文用复合泊松过程描述保费收入,从而将确定性保费收入条件下的破产概率模型拓展到随机化保费收入条件下的破产概率模型,在此基础上模拟计算了保险公司破产概率,并比较分析了不同的保险资金投资模式对破产概率的影响。     

一类相同材料焊接问题的稳定性

文章讨论了相同材料带一个孔洞无限平面焊接问题的稳定性,通过引进两个全纯函数,把焊接问题转化为黎曼边值问题中的跳跃问题,从而得到应力函数的表达式,借助柯西型积分关于积分曲线和核密度的稳定性来研究其稳定性,并给出误差估计。     

要素价格扭曲与异质性企业区位选择——基于泊松面板回归的实证研究

采用生产函数法,论文详细测算了1998-2007年中国大陆除西藏以外267个城市的要素价格扭曲。接下来,运用中国工业企业数据库中的数据,构建泊松面板回归模型考察了要素价格扭曲对于不同生产效率企业选址产生的影响。按行业、区域分别划分样本以及稳健性检验均表明:(1)较高的要素价格扭曲水平对于该地区新进入的低效率企业的期望值具有显著为正的影响,而对于该地区新进入的高效率企业的期望值则具有显著为负的影响;(2)地区运输成本和环境管制强度对于不同效率企业选址的影响存在异质性,而其他区域特征解释变量对于选址企业数量的影响均显著,且方向与理论预期一致。     

Gravity Models of Interregional Migration in Indonesia

This article explores the determinants of interregional migration in Indonesia. Employing basic and modified (extended) gravity models, and using data from the 2000 and 2010 Population Censuses and the 2005 Intercensal Population Survey, we test Long’s (1985) hypothesis that in the early stages of population redistribution, economic development is positively related to a concentration of the population. Using per-capita GDP as a proxy for income and as an indicator of economic development, we find that migration in Indonesia is indeed directed towards more developed regions. This finding supports the notion that regional disparities in development are an important factor in interregional migration in Indonesia. In line with classical gravity models, our findings show that distance is negatively related to the size of migration flows. However, unlike previous studies of interprovincial migration in Indonesia, we find that the effect of distance has weakened over time.     

基于Portal的企业综合平台设计与实现

企业信息化的发展一般基于部门及其业务条线,由此造成系统间互操作困难、数据无法共享以及信息化整体应用水平不高。文章采用基于ESB企业服务总线及Portal技术,提出实现界面、业务及数据的集成方案,并由此进行门户的设计与实现其应用。     

Worldviews,Levels of Consciousness,and the Evolution of Planning Paradigms in Protected Areas

Abstract

Protected areas (PAs) worldwide are facing increasing visitation and complexity. Mounting pressures from the private sector are intensifying the risks associated with overtourism. The increasing strategic importance of PAs for the communities and regions in which they are situated requires improved management effectiveness; yet, recent studies indicate significant and growing systemic risk. Worldview analysis can be a valuable tool for building consciousness and informing the evolution of PA planning and management. Directed content analysis was used to examine two Visitor Use Plans developed for the Coyhaique National Reserve, located in the iconic Patagonia cultural area of southern Chile. The plans were developed using distinct planning frameworks, with different underlying assumptions. Research questions focused on how modernist, postmodernist and integral worldviews were expressed within the two plans. Worldviews were explored in both manifest and latent manners, considering plan text, models and overall context revealing patterns and links between the plans and planning frameworks that guided their development. Rich context and a thorough discussion of methods assists with the incorporation of worldview evaluation within PA management theory, informing the continuing development of knowledge and capacities that can better prepare PAs for future challenges.     

Compound mixed Poisson distributions I

The concept of compound mixed Poisson distributions in actuarial science is used to represent such variables as the total amount of claims or losses payable by an insurer. In this paper, comprehensive collections of approximate forms are derived for the compound mixed Poisson distribution. The calculations involve use of several special functions and their properties. We believe that the results will serve as an important reference in actuarial science.     

Mean and dispersion modelling for policy claims costs

A model for the statistical analysis of the total amount of insurance paid out on a policy is developed and applied. The model simultaneously deals with the number of claims (zero or more) and the amount of each claim. The number of claims is from a Poisson-based discrete distribution. Individual claim sizes are from a continuous right skewed distribution. The resulting distribution of total claim size is a mixed discrete-continuous model, with positive probability of a zero claim. The means and dispersions of the claim frequency and claim size distribution are modeled in terms of risk factors. The model is applied to a car insurance data set.     

Optimal dividend policies for piecewise-deterministic compound Poisson risk models

This paper considers the optimal dividend payment problem in piecewise-deterministic compound Poisson risk models. The objective is to maximize the expected discounted dividend payout up to the time of ruin. We provide a comparative study in this general framework of both restricted and unrestricted payment schemes, which were only previously treated separately in certain special cases of risk models in the literature. In the case of restricted payment scheme, the value function is shown to be a classical solution of the corresponding HJB equation, which in turn leads to an optimal restricted payment policy known as the threshold strategy. In the case of unrestricted payment scheme, by solving the associated integro-differential quasi-variational inequality, we obtain the value function as well as an optimal unrestricted dividend payment scheme known as the barrier strategy. When claim sizes are exponentially distributed, we provide easily verifiable conditions under which the threshold and barrier strategies are optimal restricted and unrestricted dividend payment policies, respectively. The main results are illustrated with several examples, including a new example concerning regressive growth rates.     

中国反倾销对国外对华反倾销有遏制作用吗？

改革开放以来中国迅速成为全球首要的反倾销目标国家,中国制定实施反倾销法具有遏制国外对华滥用反倾销措施的动机。文章利用负二项模型和泊松模型对1995—2008年20个国家（地区）对华反倾销调查数据进行计量分析,发现中国对进口产品实施反倾销以及主动利用WTO争端解决机制挑战他国对华反倾销行为并未对国外对华反倾销产生明显的遏制作用。要改变中国在全球反倾销博弈中的不利处境,一要积极推动WTO反倾销制度改革,防止进口国滥用反倾销措施;二要增强对外反倾销的针对性;三要提升主动利用WTO争端解决机制处理反倾销争议的能力。