A correlation-formula

Abstract

The late Professor T. N. THIELE has pointed out, ¹ Bulletins de l'Académie Royale de Danemark, 1906 N:o 3 p. 149–152. that a given correlation may sometimes be brought to vanish by a suitable linear transformation of the coordinates. Unfortunately his indications in this respect are very brief; and as the subject is not treated by means of frequency-surfaces, but only by a consideration of the first few moments (or rather “half-invariants ” ² A kind of rational functions of the moments, see THIELE: Theory of Ohservations, London 1903, p. 24. — The same incomplete method has heen applied by C. Burrau (Meddelelser fra den antropologiske Komite p. 243–260). ) in a particular numerical case, his efforts have not resulted in establishing a correlation-formula which alone, by comparison with the observations, could prove his assertion right or wrong. I therefore propose to resume the subject, beginning with a few remarks on frequency-distributions with one single variable, and repeating, for the sake of completeness, a certain amount of known matter.     

一种基于物流市场的网格Web服务资源分配模型

本文在OGSA、WSRF和WS-Notification基础上提出了一种基于物流市场的网格Web服务资源分配模型。该模型充分利用了物流技术的特点,使网格Web服务资源得到有效分配和利用。该模型适合广域环境,是一种有效合理的网格Web服务资源分配模型。     

网络在城市老年人服务体系中的应用模式研究

本文在"三网融合"的背景下,以老年人服务体系信息化为出发点,按照"管理主体+运作主体+网络工具"的方法提炼概括网络在我国现行老年人服务体系中的应用模式,梳理阐释各应用模式的组织形式、服务对象、服务内容、运作形式等4个维度的特征并评述。     

Stochastic Orderings of Convex-Type for Discrete Bivariate Risks

New classes of order relations for discrete bivariate random vectors are introduced that essentially compare the expectations of real functions of convex-type of the random vectors. For the actuarial context, attention is focused on the so-called increasing convex orderings between discrete bivariate risks. First, various characterizations and properties of these orderings are derived. Then, they are used for comparing two similar portfolios with dependent risks and for constructing bounds on several multilife insurance premiums.     

A Stochastic Correlation Model with Mean Reversion for Pricing Multi-Asset Options

We set up a new kind of model to price the multi-asset options. A square root process fluctuating around its mean value is introduced to describe the random evolution of correlation between two assets. In this stochastic correlation model with mean reversion term, the correlation is a random walk within the region from −1 to 1, and it is centered around its equilibrium value. The trading strategy to hedge the correlation risk is discussed. Since a solution of high-dimensional partial differential equation may be impossible, the Quasi-Monte Carlo and Monte Carlo methods are introduced to compute the multi-asset option price as well. Taking a better-of two asset rainbow as an example, we compare our results with the price obtained by the Black–Scholes model with constant correlation.     

A General Stationary Stochastic Regression Model for Estimating and Predicting Beta

A beta regression model is proposed where the coefficients follow a general class of stationary stochastic processes. The procedure identifies the process and estimates the parameters of the model simultaneously from the information contained in the return series. The returns of each of the Dow Jones 30 securities are examined. Betas of 5 of the securities are nonstationary and do not appear to follow a particular form of nonstationarity. Conclusions of many earlier studies may be suspect since they are based on procedures tailored to adoption of a specific form of beta nonstationarity and, thereby, based on an erroneous a priori assumption regarding such form. The ordinary least squares model is also found to be quite robust, providing reliable beta and intercept estimates not materially different from the more complex procedure with 25 of the return series.     

我国居家养老中社区为老服务的均等化研究

随着国家对建立居家养老服务体系的不断重视,城乡社区为老服务得到较快发展。但是,我国目前社区为老服务存在着明显的不均等现象,城市多于农村,东部地区多于中西部地区,同时,各类社区服务供给和需求上还明显存在三类矛盾,因此,需要针对城乡和不同地区社区为老服务的实际情况与老年人的需求状况分别制定相应的措施。     

两因子随机死亡率状态空间模型及长寿风险测度

引入状态空间模型对传统两因子CBD模型拟合阶段和预测阶段进行联合建模,并基于卡尔曼滤波方法对模型参数进行估计。进一步考虑到死亡率数据的小样本特征,结合Bootstrap仿真技术和生存年金组合折现模型对长寿风险进行测度。利用1996~2011年数据展开实证研究,结果表明:结合模型解释能力、参数估计结果和误差项正态分布检验结果,两因子状态空间模型要优于传统CBD模型;年金组合规模的扩大可以消除微观长寿风险,但不能消除宏观长寿风险和参数风险;宏观长寿风险占据着不可分散风险的主导地位。     

澳大利亚纳税服务经验及对我国的启示

本文介绍了澳大利亚税务局纳税服务的基本情况,从纳税服务理念、纳税服务措施和税务代理纳税服务等几个方面阐述了澳大利亚纳税服务的经验,并对优化我国纳税服务提出了建议。     

符号分析服务对未来工作的挑战

信息时代的到来,软件技术的发展,已经完全改变了我们的工作方式。符号分析人员在未来的工作中越来越占有主导地位。这是现实工作的创举,也是强劲的挑战,迎接这种挑战是当前人类最重要的任务。     

A Two-Factor Model for Stochastic Mortality with Parameter Uncertainty: Theory and Calibration

In this article, we consider the evolution of the post‐age‐60 mortality curve in the United Kingdom and its impact on the pricing of the risk associated with aggregate mortality improvements over time: so‐called longevity risk. We introduce a two‐factor stochastic model for the development of this curve through time. The first factor affects mortality‐rate dynamics at all ages in the same way, whereas the second factor affects mortality‐rate dynamics at higher ages much more than at lower ages. The article then examines the pricing of longevity bonds with different terms to maturity referenced to different cohorts. We find that longevity risk over relatively short time horizons is very low, but at horizons in excess of ten years it begins to pick up very rapidly. A key component of the article is the proposal and development of a method for calculating the market risk‐adjusted price of a longevity bond. The proposed adjustment includes not just an allowance for the underlying stochastic mortality, but also makes an allowance for parameter risk. We utilize the pricing information contained in the November 2004 European Investment Bank longevity bond to make inferences about the likely market prices of the risks in the model. Based on these, we investigate how future issues might be priced to ensure an absence of arbitrage between bonds with different characteristics.     

A Complete Markovian Stochastic Volatility Model in the HJM Framework

This paper considers a stochastic volatility version of the Heath, Jarrow and and Morton (1992) term structure model. Market completeness is obtained by adapting the Hobson and Rogers (1998) complete stochastic volatility stock market model to the interest rate setting. Numerical simulation for a special case is used to compare the stochastic volatility model against the traditional Vasicek (1977) model.     

优化纳税服务渠道的国际经验及借鉴

纳税服务渠道综合了为纳税人服务的各项资源和具体措施,是税务机关提供纳税服务、提升管理效率的重要依托。本文介绍了国外纳税服务渠道建设的先进经验,分析了我国纳税服务渠道建设存在的问题,并提出了建设以纳税人为导向的整体纳税服务渠道策略的若干建议。     

Effectiveness of Stochastic Neural Network for Prediction of Fall or Rise of TOPIX

Stochastic neural network is a hierarchical network of stochastic neurons which emit 0 or 1 with the probability determined by the values of inputs. We have developed an efficient training algorithm so as to maximize the likelihood of such a neural network. This algorithm enables us to apply the stochastic neural network to a practical problem like prediction of fall or rise of Tokyo Stock Price Index (TOPIX). We trained it with the data from 1994 to 1996 and predicted the fall or rise of 1 day ahead of TOPIX for the period from 1997 to 2000. The result is quite promising. The accuracy of the prediction of the stochastic network is the 60.28%, although those of non-stochastic neural network, autoregressive model and GARCH model are 50.02, 51.38 and 57.21%, respectively. However, the stochastic neural network is not so advantageous over other networks or models for prediction of the TOPIX used for training. This means that the stochastic neural network is less over fitting to the training data than others, and results in the best prediction. We will demonstrate how the stochastic neural network learns well non-linear structure behind of the data in comparison to other models or networks, including Generalized Linear model (GLM).JEL codes: D24, L60, 047     

浅议税收执法和纳税服务

税收执法与纳税服务是法律赋予税务机关的重要职责,两者之间是相辅相成的关系。本文尝试运用经济学中的最优理论来分析税收执法问题,试图阐述其与传统分析不同的经济学涵义,并结合我国税收实践,就合理处理税收执法与纳税服务关系提出建议。     

Insurance Considering a New Stochastic Model for the Discount Factor

In many empirical situations (e.g.: Libor), the rate of interest will remain fixed at a certain level (random instantaneous rate i i ) for a random period of time ( t i ) until a new random rate should be considered, i i + 1 , that will remain for t i + 1 , waiting time until the next change in the rate of interest. Three models were developed using the approach cited above for random rate of interest and random waiting times between changes in the rate of interest. Using easy integral transforms (Laplace & Fourier) we will be able to calculate the moments of the probability function of the discount factor, V ( t ), and even its c.d.f. The approach will also be extended to the calculation of the expected value (net premium) and variance of a term insurance and we will get its c.d.f., something not very common in actuarial literature due to its complexity, but very useful when the law of large numbers cannot be applied and consequently use normal approximations.     

A Remark on a Singular Perturbation Method for Option Pricing Under a Stochastic Volatility Model

This paper studies the approximation accuracy of a singular perturbation method for option pricing up to the second order under a stochastic volatility model. First, numerical experiments confirm that the first order approximation provides sufficiently accurate option prices in a fast mean-reversion volatility case. On the other hand, it creates relatively large errors in a non-fast mean-reversion volatility environment. Then, the second order approximation formula is derived and the improvement of the approximation is investigated.     

地方政府公共服务职能研究

在我国现阶段,由于长期以来重经济轻服务的倾向,导致公共服务投入不足,供需矛盾突出,而地方政府贴近公众日常生活,相比中央政府更容易了解民众的公共需求,因此,针对目前地方政府公共服务职能存在的问题,中央与各级地方政府要上下联动,采取措施转变地方政府职能,加强地方政府的公共服务职能。     

A Generalized Spatial Two-Stage Least Squares Procedure for Estimating a Spatial Autoregressive Model with Autoregressive Disturbances

Cross-sectional spatial models frequently contain a spatial lag of the dependent variable as a regressor or a disturbance term that is spatially autoregressive. In this article we describe a computationally simple procedure for estimating cross-sectional models that contain both of these characteristics. We also give formal large-sample results.     

构建网络时代商业银行营业网点柜面服务新模式

营业网点是商业银行业务经营管理的重要阵地,其柜面服务更是商业对外服务的重要渠道之一.商业银行在网络化发展中,营业网点的柜面服务不但发生了巨大变化,而且也产生了许多新的问题.本文借鉴国际银行业在网络时代营业服务发展趋势,提出商业银行应充分发挥网络优势,以客户为中心,重构营业网点服务体系,提升柜面服务层次;深化核算管理一体化改革,创新柜面服务模式;改进业务产品创新机制,提高网点竞争能力;加快柜面业务流程再造,改善网点服务效能;改造营业网点柜台设置,推行功能分区服务;改进营业网点内部管理,提高柜面服务质量,全面提升网络时代营业网点柜面服务水平.