On a preliminary test estimator for one of the parameters of the log-zero-poisson distribution

A discrete distribution called the log-zero-Poisson distribution has been recommended by Katti (c.f. Biometrics 1970) as an alternate to the negative binomial and other distributions usually called "contagious" distributions.A major problem in the use of this and all other contagious distributions has been the difficulty of obtaining the maximum likelihood esti-mates. A custom-made ad hoc estimator, λ, has been proposed for the parameter λ of this distribution in Katti and Khedr (1980). In this paper, its efficiency relative to Fisher information is studied, only to discover that λ can be 30 times better than the maximum likelihood estimate in some parts of the parameter space and much weaker in other parts.A preliminary test is recommended to choose between the estimates, and the efficiency of the procedure is tabulated. As it is to be expected, the resultant estimator equals the better of the two estimators with some error at the values of the parameters where the two estimators are equivalent.     

对"SARS"疫灾的理性审视

“SARS”———这一传染性极强的突发疾病挟死亡阴影煽动起的恐慌 ,借助最先进发达的信息传布网络 ,在虚拟和现实的两度空间不断地相互映射、碰撞、放大 ,弥散……疫灾不仅影响市场秩序 ,也影响人们的日常生活和社会的稳定。在经历这场疫灾之后 ,政府、民众必须以理性的心态对其加以审视。     

论强势广告语言模因之形成要素

在模因论中,模因学家将广告这一不断在人们大脑之间复制传播的复制因子视为一种模因。而那些能够在激烈的竞争中脱颖而出,成为经典的广告往往被认为是强势广告模因。文章以模因理论为基础,从强势模因的特点和传播的过程这两方面来探讨成为强势广告语言模因的形成要素,希望能够为广告人如何设计成功的广告提供一条新的思路。     

宏观审慎监管对传染性银行风险的控制作用研究

针对金融危机暴露出的传染性银行风险对金融稳定危害增大的现象,通过分析宏观审慎工具对于不同风险传染渠道的控制作用,以Rochet模型为基础建立宏观审慎模型,从理论和模型的角度论证了宏观审慎监管对传染性银行风险的控制作用并分析了作用机制,同时选取中国商业银行合并数据,对不同政策工具组合的作用效果进行了实证研究,证明现阶段监管工具中存款准备金率的控制效果最显著,应完善宏观审慎监管框架,构建宏观审慎监管工具组合对传染性银行风险进行控制。     

殷墟卜辞所见我国最早的传染流疫考

《合集》137正片中记载了武丁时期在郸城、■子、鬼(方)等地区与方国流行的传染性病疫情况,另外《合集》13887与《合集》17446片也有与流行性病疫有关的记载,说明其时商王是很关注流疫沴气的情况。这是我国最早所见的武丁时期有关病毒性传染流疫的记录。此片中"■"之"■"应读为"逢",并从字形、音义和用法对反映流疫的专用字"■(沴)"字作了详细的考证。     

Efficiency of an adaptive estimator of a log-zero-poisson parameter

An estimator, λ is proposed for the parameter λ of the log-zero-Poisson distribution. While it is not a consistent estimator of λ in the usual statistical sense, it is shown to be quite close to the maximum likelihood estimates for many of the 35 sets of data on which it is tried. Since obtaining maximum likelihood estimates is extremely difficult for this and other contagious distributions, this estimate will act at least as an initial estimate in solving the likelihood equations iteratively. A lesson learned from this experience is that in the area of contagious distributions, variability is so large that attention should be focused directly on the mean squared error and not on consistency or unbiasedness, whether for small samples or for the asymptotic case. Sample sizes for some of the data considered in the paper are in hundreds. The fact that the estimator which is not a consistent estimator of λ is closer to the maximum likeli-hood estimator than the consistent moment estimator shows that the variability is large enough to not permit consistency to materialize even for such large sample sizes usually available in actual practice.     

金融危机期间汇率风险传染研究

选取2000年—2016年欧元区国家、欧盟非欧元区国家、部分发达国家以及金砖五国等47个国家的货币汇率数据为样本,使用相关系数的费雪Z转换来检验次贷危机和欧洲主权债务危机的汇率风险传染效应,并将其进一步细分为净传染和转移传染两种类型.研究表明,两次金融危机爆发后,样本国家的外汇市场均出现大幅度震荡,但主要表现为汇率市场间的相互依赖关系,仅有少数国家货币汇率与传染源之间存在传染效应,其中,次贷危机期间转移传染效应明显,欧债危机期间净传染效应显著,可见实体经济间的联系和投资者心理预期对外汇市场的影响均较大.     

金融危机传染路径的空间统计分析

 本文采用空间统计分析方法对金融危机分布的空间集聚性和传染路径进行了实证分析。结果表明：美国次贷危机的传染路径有：地理区域位置、G7政治集团关系、贸易关系和资本项目开放度。东南亚金融危机的传染路径有：地理区域位置、贸易关系以及资本项目开放度。并与´Alvaro A. Novo对1992年欧洲金融危机传染路径的研究进行了比较。     

An extended exponentiated-G-negative binomial family with threshold effect

In this paper, we formulate a very flexible family of models which unifies most recent lifetime distributions. The main idea is to obtain a cumulative distribution function to transform the baseline distribution with an activation mechanism characterized by a latent threshold variable. The new family has a strong biological interpretation from the competitive risks point of view and the Box–Cox transformation provides an elegant manner to interpret the effect on the baseline distribution to obtain this alternative model. Several structural properties of the new model are investigated. A Bayesian analysis using Markov Chain Monte Carlo procedure is developed to illustrate with a real data the usefulness of the proposed family.