The Risk of a Mortality Catastrophe

We develop a continuous-time model for analyzing and valuing catastrophe mortality contingent claims based on stochastic modeling of the force of mortality. We derive parameter estimates from a 105-year time series of U.S. population mortality data using a simulated maximum likelihood approach based on a particle filter. Relying on the resulting parameters, we calculate loss profiles for a representative catastrophe mortality transaction and compare them to the “official” loss profiles that are provided by the issuers to investors and rating agencies. We find that although the loss profiles are subject to great uncertainties, the official figures fall significantly below the corresponding risk statistics based on our model. In particular, we find that the annualized incidence probability of a mortality catastrophe, defined as a 15% increase in aggregated mortality probabilities, is about 1.4%—compared to about 0.1% according to the official loss profiles.     

A Martingale-based bootstrap inference with censored data

In this paper, me shall investigate a bootstrap method hasd on a martingale representation of the relevant statistic for inference to a class of functionals of the survival distribution. The method is similar in spirit to Efron's (1981) bootstrap, and thus in the present paper will be referred to as “martingale-based bootstrap” The method was derived from Lin,Wei and Ying (1993), who appiied the method in checking the Cox model with cumulative sums of martingale-based residuals. It is shown that this martingale-based bootstrap gives a correct first-order asymptotic approximation to the distribution function of the corresponding functional of the Kaplan-Meier estimator. As a consequence, confidence intervals constructed by the martingale-based bootstrap have asymptotially correct coverage probability. Our simulation study indicats that the martingale-based bootst strap method for a small and moderate sample sizes can be uniformly better than the usual bootstrap method in estimating the sampling distribution for a mean function and a point probability in survival analysis.     

部分信息下实物期权的定价和风险对冲

当前所有实物期权理论研究都是基于完全信息(full information)假设.本文则通过研究投资者在部分信息(partial information)下极大化无限期消费效用的最优投资消费问题,得出实物期权的消费效用无差别价格.通过控制系统的分离原理,运用Kalman滤波技术和随机控制方法,得到了CARA效用函数情形下实物期权的自由边界偏微分方程.利用有限差分法,解得实物期权的隐含价值及最优执行水平从而得到最优投资消费策略和效用函数的数值解.通过蒙特卡洛模拟,给出了投资者在完全信息和部分信息下的动态决策差异,并且通过比较两种信息水平下的投资者福利给出了信息价值的测算.     

中国股票关联网络拓扑性质与聚类结构分析

复杂网络理论是研究股票市场内在结构和功能的有力工具,股票关联网络的拓扑性质和聚类结构对于理解网络的形成机制、发生在网络上的动力学行为具有重要意义.以中国上证180指数和深证100指数成分股票为研究标的,运用最小生成树算法和平面最大过滤图算法构建相应的股票关联网络,分析网络的基本拓扑统计性质和聚类结构.实证研究表明,平面最大过滤图关联网络为小世界网络,各关联网络内股票的影响强度服从幂律分布,股票之间存在的异类匹配模式揭示了市场内股票价格波动传导的过程,对最小生成树关联网络和平面最大过滤图关联网络的宗派和派系聚类分析能有效地挖掘股票之间的聚类结构信息,总体上看平面最大过滤图算法优于最小生成树算法,且实证结论对沪深股票市场具有普适性.     

On the estimation of the stochastic intensity and the parameters of neyman-scott trigger processes

In this paper we are concerned with a class of simple point processes, whose unobservable stochastic intensity is a shot-noise process. We derive a stochastic equation for the conditional moment generating function of the intensity, which can be solved in a recursive way. This yields explicit expression for the minimum variance estimate of the intensity as well as the likelihood ration with respect to the reference measure, on the basis of point process observations.     

A Review of Some Modern Approaches to the Problem of Trend Extraction

This article presents a review of some modern approaches to trend extraction for one-dimensional time series, which is one of the major tasks of time series analysis. The trend of a time series is usually defined as a smooth additive component which contains information about the time series global change, and we discuss this and other definitions of the trend. We do not aim to review all the novel approaches, but rather to observe the problem from different viewpoints and from different areas of expertise. The article contributes to understanding the concept of a trend and the problem of its extraction. We present an overview of advantages and disadvantages of the approaches under consideration, which are: the model-based approach (MBA), nonparametric linear filtering, singular spectrum analysis (SSA), and wavelets. The MBA assumes the specification of a stochastic time series model, which is usually either an autoregressive integrated moving average (ARIMA) model or a state space model. The nonparametric filtering methods do not require specification of model and are popular because of their simplicity in application. We discuss the Henderson, LOESS, and Hodrick–Prescott filters and their versions derived by exploiting the Reproducing Kernel Hilbert Space methodology. In addition to these prominent approaches, we consider SSA and wavelet methods. SSA is widespread in the geosciences; its algorithm is similar to that of principal components analysis, but SSA is applied to time series. Wavelet methods are the de facto standard for denoising in signal procession, and recent works revealed their potential in trend analysis.     

视听传播的艺术观照

"超文本"的电视文化高速发展表现在两个方面:一是通过国际卫星接收国际频道,提升全球化、国际化水平;二是有线电视、家庭录像机和影碟机的发展,扩大人们的选择余地。自我创造并参与中国文化创造的中国电视文化正在全面走向成熟,其影响力表现在三个方面:一是由集体性转向个体性话语,确认"个人主体"价值;二是将传统文化移入全球性文化空间,促进中国"现代性"焦虑形成;三是经历了由无到有、由少至多的高速成长过程,具有极强的过渡性。其定位也由模糊到明确。由于"技术滤器"作用电视具有特殊的表现形式和工作方式,传播文化革命冲击了电视新闻、记录片、体育、文艺、广告等节目形态。     

Risk filtering, ranking, and management framework using hierarchical holographic modeling.

This paper contributes a methodological framework to identify, prioritize, assess, and manage risk scenarios of a large-scale system. Qualitative screening of scenarios and classes of scenarios is appropriate initially, while quantitative assessments may be applied once the set of all scenarios (hundreds) has been prioritized in several phases. The eight-phase methodology is described in detail and is applied to operations other than war. The eight phases are as follows: Phase I, Scenario Identification-A hierarchical holographic model (HHM) is developed to describe the system's "as planned" or "success" scenario. Phase II, Scenario Filtering-The risk scenarios identified in Phase I are filtered according to the responsibilities and interests of the current system user. Phase III, Bi-Criteria Filtering and Ranking. Phase IV, Multi-Criteria Evaluation. Phase V, Quantitative Ranking-We continue to filter and rank scenarios based on quantitative and qualitative matrix scales of likelihood and consequence; and ordinal response to system resiliency, robustness, redundancy. Phase VI, Risk Management is performed, involving identification of management options for dealing with the filtered scenarios, and estimating the cost, performance benefits, and risk reduction of each. Phase VII, Safeguarding Against Missing Critical Items--We examine the performance of the options selected in Phase VI against the scenarios previously filtered out during Phases II to V. Phase VIII, Operational Feedback-We use the experience and information gained during application to refine the scenario filtering and decision processes in earlier phases. These eight phases reflect a philosophical approach rather than a mechanical methodology. In this philosophy, the filtering and ranking of discrete scenarios is viewed as a precursor to, rather than a substitute for, consideration of the totality of all risk scenarios.     

基于最优估计理论的上市公司永久性盈余估计

估计上市公司的永久性盈余对进行股票投资是非常重要的.本文应用最优估计理论中的卡尔曼滤波和强跟踪滤波方法对上市公司的永久性盈余进行动态估计.实证结果表明基于强跟踪滤波的估计比基于卡尔曼滤波的估计精确许多.