An information-theoretic approach to incorporating prior information in binomial sampling

The incorporation of prior information about θ, where θ is the success probability in a binomial sampling model, is an essential feature of Bayesian statistics. Methodology based on information-theoretic concepts is introduced which (a) quantifies the amount of information provided by the sample data relative to that provided by the prior distribution and (b) allows for a ranking of prior distributions with respect to conservativeness, where conservatism refers to restraint of extraneous information about θ which is embedded in any prior distribution. In effect, the most conservative prior distribution from a specified class (each member o f which carries the available prior information about θ) is that prior distribution within the class over which the likelihood function has the greatest average domination. The most conservative prior distributions from five different families of prior distributions over the interval (0,1) including the beta distribution are determined and compared for three situations: (1) no prior estimate of θ is available, (2) a prior point estimate or θ is available, and (3) a prior interval estimate of θ is available. The results of the comparisons not only advocate the use of the beta prior distribution in binomial sampling but also indicate which particular one to use in the three aforementioned situations.     

A target distribution model for nonparametric density estimation

In this paper a model is proposed which represents a wide class of continuous distributions. It is shown how the parameters of this model can be estimated leading to a distribution estimator and a corresponding density estimator. An important property of this estimator is that it can be structured to reflect a priori knowledge of the unknown distribution.

Finally, some examples are shown and some comparisons made with kernel and orthogonal series estimators.     

A structural model for the markov chain of change in vote intention

Assuming a first-order Markov chain, we propose a structural model for the transition probabilities in vote intention. The proposed model utilizes the ordering among the categories representing vote intentions and carries the flavor of distance models. It also allows a stochastic ordering among distributions reflecting the extent of change. The model is easy to fit and provides a nice interpretation of the data. The model is applied to a panel study of vote intention acquired through six successive interviews before the 1940 Presidential election in Erie County, Ohio.     

中国绿色全要素生产率测算及分解:1985~2010

现有文献在我国全要素生产率方面已经得到了很多有价值的研究结论,但不可否认的是,单纯考虑中国经济增长而忽略了资源环境因素对经济质量的影响是片面的。与类似研究相比,本文在生产率测量框架体系中引入了资源环境因素,从而为我国经济增长质量的测度提供一个更为科学的方法。文章分别运用基于DEA的Malmquist生产率指数和基于方向性距离函数的Malmquist-Luenberger生产率指数对1985～2010年间中国绿色全要素生产率进行了测算及分解。研究发现,不考虑资源环境因素会高估全要素生产率,从而对我国经济增长质量做出较为乐观的判断;我国全要素生产率增长主要来源于技术进步;考察期内我国绿色全要素生产率呈现“先升后降再平稳”的时间趋势特征,且显示出较大的地区差异。     

保持现代远程教育稳健发展应把握的几个要素

保持现代远程教育稳健发展应注重远程教育理论的研究和创新,远程教育学科的建立和师资的培养,处理好质量、规模和效益三者的关系,多种教学媒体的开发、整合和利用,教学模式和管理模式的改革与完善五个主要因素。     

题材与距离

城市题材难写,工业题材尤难,文坛早有定论。这在相当程度上乃是距离在起微妙而神秘的作用。题材与审美者地理距离相隔越远,作品就越容易出彩。工业题材、城市题材虽然难,但决非碰不得沾不得,关键还在于作家要舍得投入。题材差别与审美距离都是相对的,作家个人的艺术坚持与艺术求索才是绝对的。     

基于智能体的远程教学系统

本文通过对智能体定义的评述，总结了智能体应具有的若干主要性质，提出了基于多智能体的智能远程教学系统模型，对系统的各个模块进行了定义。     

Borda and Condorcet: Some Distance Results

This paper provides a distance based analysis of the Borda rule with respect to Condorcet’s criterion. It shows that the minimal Condorcet consistency present in the Borda rule, whenever a Condorcet winner (the alternative that wins against every other alternative in a pairwise contest) exists, disappears in the case of voting cycles. First, it is shown that for certain preference profiles the Borda winner is furthest from being a Condorcet winner. Second, it is shown that there exist preference profiles for which the Borda winner is closest from being a Condorcet loser (the alternative that loses against every other alternative in a pairwise contest).     

A Probabilistic Perspective on Re-Identifiability

A quasi-identifier is a set of attributes that can be used to re-identify entries in anonymized data sets. A group of individuals is considered about whom quasi-identifying numerical information is disclosed such as date of birth, age, weight, and height. The fraction of individuals is determined whose information is unique in that group and hence is identifiable unambiguously. Nonuniformity can be captured well by a single number, the Kullback-Leibler distance. For example sets of real microdata, given approximations based on Kullback-Leibler distances are accurate. Second, the effect of disclosing more specific or less specific information is analyzed experimentally. Third, the effect of correlation between numerical attributes is measured. A formula gives the re-identifiability level. The approximations are validated using publicly available demographic data sets.     

Commenting on PC and Multiculturalism

ABSTRACT

Women Veterans who experience homelessness are at high risk of unintended pregnancy and adverse outcomes. Contraception could mitigate risks, yet access barriers exist across the Veterans Health Administration (VHA). We identified all US women Veterans, age 18–44y with evidence of homelessness in VHA administrative data between fiscal years 2002–2015, in order to document the geographic distribution of ever-homeless women Veterans in relation to VA Medical Centers (VAMCs) and assess geographic associations between long-acting reversible contraceptives (LARC) or permanent contraception (PC) use. We calculated VAMC travel distance from last known ZIP Code. We used multivariate logistic regression models to explore contraceptive method associations. We included 41,722 ever-homeless women Veterans; 9.2% had LARC exposure and 7.5% PC. We found 29% of ever-homeless women Veterans resided >40miles from the nearest VAMC and increasing drive distance was negatively correlated with contraceptive exposure, especially for Veterans residing >100miles from a VAMC. Increasing distance to the nearest VAMC results in a geographic barrier to the most effective contraceptive options for women Veterans. The VHA is uniquely positioned to leverage its rural and homeless healthcare expertise to address geographic barriers and integrate comprehensive contraceptive services into established programs for high-risk Veterans.