Pearson-Tukey Three-Point Approximations Versus Monte Carlo Simulation

Accuracy of the Pearson-Tukey three-point approximation is measured in units of standard deviation and compared with that of Monte Carlo simulation. Using a variety of well-known distributions, comparisons are made for the mean of a random variable and for common functions of one and two random variables. Comparisons are also made for the mean of an assortment of risk-analysis (Monte Carlo) models drawn from the literature. The results suggest that the Pearson-Tukey approximation is a useful alternative to simulation in risk-analysis situations.     

基于高维波动率网络模型的股票市场风险特征研究

波动率是金融风险管理研究的重要内容之一。本文基于复杂网络理论和数据挖掘技术提出股票市场的高维波动率网络模型。首先运用互信息度量不同股票价格波动之间的相关关系,其次对股票市场不同周期下的波动情况建立度的中心势、平均距离、幂律分布等网络拓扑指标,再次根据这些指标利用Prim算法构建出高维波动率网络模型,最后运用Newman-Girvan算法对股票价格波动率的相关性进行分层研究。高维波动率网络模型突破了传统波动率模型关于变量维数的限制,能够在依赖少量假设的基础上,挖掘出多个金融市场主体间的相互关系,反映金融市场的风险特征及网络拓扑性质。实证结果发现：与常用的Pearson相关系数法相比,在互信息框架下,股价波动的非线性相关关系得到了更好的度量;股票市场的整体波动性与个股波动率相关性变化趋势相反,市场处在高波动时期资产组合分散化效果较好;网络中存在少量度数大的关键节点和中心节点,风险通过这些节点可以迅速传递到整个市场;股票市场的运行具有明显的行业聚集现象;网络分层研究进一步直观的展现了风险在层与层之间的传递规律和与之对应的行业特征。高维波动率网络模型为挖掘股票市场的风险特征与管理金融风险提供了一个新的工具。     

‘Scarier than another storm’: values at risk in the mapping and insuring of US floodplains

How do people respond to the ways in which insurance mediates environmental risks? Socio‐cultural risk research has characterized and analyzed the experiential dimension of risk, but has yet to focus on insurance, which is a key institution shaping how people understand and relate to risk. Insurance not only assesses and communicates risk; it also economizes it, making the problem on the ground not just one of risk, but also of value. This article addresses these issues with an investigation of the social life of the flood insurance rate map, the central technology of the U.S. National Flood Insurance Program (NFIP), as it grafts a new landscape of ‘value at risk’ onto the physical and social world of New York City in the aftermath of Hurricane Sandy. Like other risk technologies, ubiquitous in modern societies as decision‐making and planning tools, the map disseminates information about value and risk in order to tame uncertainty and enable prudent action oriented toward the future. However, drawing together interview, ethnographic, and documentary data, I find that for its users on the ground, the map does not simply measure ‘value at risk’ in ways that produce clear strategies for protecting property values from flooding. Instead, it puts values‐beyond simply the financial worth of places‐at risk, as well as implicates past, present, and future risks beyond simply flooding. By informing and enlarging the stakes of what needs protecting, and from what, I argue that plural and interacting ‘values at risk’ shape how people live with and respond to environmental risks that are mediated by insurance technologies.     

A DECISION THEORY EXAMPLE IN FOOTBALL

In the 1967 Harvard-Cornell football game, Harvard was ahead 14–0 late in the game when Cornell scored two touchdowns. On both occasions, Cornell tried and failed on the two-point conversion attempt and lost the game 14–12. Postgame arguments were divided on the merits of Cornell's strategy. For this frequently occurring scenario in college football, we derive a maximum expected utility decision rule for the decision of kicking versus running/passing based on the relative utility of a win, a tie, or a loss and the probabilities of success with a kick as opposed to a run/pass.     

COST-VOLUME-PROFIT ANALYSIS IN STOCHASTIC PROGRAMMING MODELS

This paper applies mathematical programming to cost-volume-profit (CVP) analysis under contribution margin uncertainty. Three CVP probabilistic chance-constraint models based on various safety-first criteria for decisions under uncertainty are presented and compared. It is shown that a break-even segment of the mean-standard deviation frontier is a set of optimal solutions for the proposed models. An operational parametric quadratic programming (QP) model is constructed, and the efficiency frontier is generated. The procedures for locating an optimal solution on the efficiency frontier are then presented. The recommended QP procedure offers both technical relief from the computational difficulties posed by the probabilistic constraints and a desired flexibility in generating and presenting the relevant information for decisions under uncertainty.     

银行监管、风险承担与公司价值

商业银行具有脆弱性和负外部性等特征,再考虑到信息不对称和众多中小债权人存在,政府便伸出援助之手对银行进行广泛监管,以免银行出现过度风险承担行为从而危及整个经济体运转。银行监管旨在限制银行机构风险、维持银行体系安全,但同时亦应有助于提升银行公司价值、提高金融和经济效率。本文着重分析了主要监管措施对银行风险承担和公司价值的影响,试图总结出各项监管措施的有效性。通过多国截面数据的实证模型我们发现,信息披露是激励相容的,资本充足要求和银行安全网有利于降低风险承担却不利于公司价值,而市场准入正好相反,监管权力、业务限制对两者均有反面影响。     

资本外逃的成因:文献评述及政策含义

国外理论界对于资本外逃成因诠释的文献,主要有资产组合理论、人力资本理论、政党轮流执政理论、公共地悲剧理论和政治风险理论,这些理论从不同角度诠释了资本外逃产生的原因及其内在机制,从一个侧面体现了经济学研究的方法论,从早期的文字阐述到模型的构建,从早期的假说、推测到近期的计量分析验证的演进轨迹。     

农村独生子女家庭的医疗保障问题思考

农村独生子女家庭,由于传统的家庭风险分担机制对他们无法发挥作用,而面临着三代人的医疗风险,成为高医疗风险家庭.但当前我国农村正在构筑新的社会医疗保障制度,并没有对农村独生子女家庭给予有效关注.国家应以农村医疗保障制度为基础,在有条件地区应鼓励并资助农村独生子女家庭参加商业医疗保险计划,并通过尽快建立健全农村社会保障制度,打破城乡二元经济结构,实现城乡协调发展,从根本上解决农村独生子女家庭的医疗问题.     

论企业信用风险的管理与控制

随着我国市场经济的进一步发展,以赊销为代表的信用销售发展也很快。如何加强应收账款管理,防范信用风险,避免坏账损失,成为众多企业面临的一个重大问题。作者对此问题进行了分析,阐述了当前企业信用风险的现状与成因,并结合我国国情和企业实际,探讨了在新形势下有关信用风险的管理与控制问题。     

分红型寿险产品保单红利所得税税制研究

目前,对分红险的保单红利是否应该征收个人所得税;在保险业界和税务部门以及学术界都存在争议。文章在借鉴国外分红脸保单红利个人所得税税制的基础上,结合我国分红脸的发展特点,提出应该适时建立分红险保单红利所得税税制。该税制的设计应遵循公平和效率原则,采用税延型的代扣代缴方式予以征税,征税范围应为超出保险成本部分、利差部分以及保单红利的生息部分。最后文章从税务机关的主张和文章的建议税制两个方面对开征保单红利所得税对寿险业的影响进行了比较分析,得出了文章的建议税制在保单持有人的保单收益和税务机关的征税总额方面优势明显的结论。