Moment-Implied Densities: Properties and Applications

Suppose one uses a parametric density function based on the first four (conditional) moments to model risk. There are quite a few densities to choose from and depending on which is selected, one implicitly assumes very different tail behavior and very different feasible skewness/kurtosis combinations. Surprisingly, there is no systematic analysis of the tradeoff one faces. It is the purpose of the article to address this. We focus on the tail behavior and the range of skewness and kurtosis as these are key for common applications such as risk management.     

Multivariate normal mean-variance mixture distribution based on Lindley distribution

This article introduces a new asymmetric distribution constructed by assuming the multivariate normal mean-variance mixture model. Called normal mean-variance mixture of the Lindley distribution, we derive some mathematical properties of the new distribution. Also, a feasible maximum likelihood estimation procedure using the EM algorithm and the asymptotic standard errors of parameter estimates are developed. The performance of the proposed distribution is illustrated by means of real datasets and simulation analysis.     

机会不平等的衡量：参数测度法的应用与改进

本文在考虑不可测环境和努力变量的影响,以及处理环境和努力变量相关性的基础上,改进机会不平等的参数测度法,并运用这一方法对中国居民收入分配的机会不平等程度进行数量测度。结果显示：样本期间,机会不平等占收入不平等的比例平均达到29%左右;分解结果显示,可测环境变量导致的机会不平等占收入不平等的比重维持在27%左右,不可测环境变量对收入不平等的贡献平均而言只有2%左右。此外,家庭教育背景差异、区域差距、城乡差距和性别歧视构成了现阶段中国居民机会不平等的主要来源。本文认为,为降低中国居民收入的机会不平等程度,政府应对因外部环境不利而陷入贫困的居民进行救济和补偿,为弱势群体依靠自己的努力取得成功创造条件和提供平台。     

真实固定效应空间随机前沿模型的贝叶斯估计

忽略个体效应和空间效应会严重干扰效率测算,其中忽略个体效应使得技术无效率项发生偏移,忽略空间相关性导致估计量有偏且不一致。本文基于真实固定效应随机前沿模型（引入了个体效应）,引入因变量和双边误差项的空间滞后项,构建了适用性更佳的真实固定效应空间随机前沿模型。对模型进行组内变化以消除额外参数,使用贝叶斯方法（需推导未知参数的后验分布并执行MCMC抽样）估计参数和技术效率。该方法真正克服了额外参数问题,比同类方法直观、简便。数值模拟结果表明,本文方法对参数、个体截距项及技术无效率项的估计精度均较高,且增加样本容量,估计精度变优。     

A bivariate distribution with Lomax and geometric margins

We develop a stochastic model describing the joint distribution of $(X,N)$, where $N$ has a geometric distribution while $X$ is the sum of $N$ dependent, heavy-tail Pareto components. Models of this form arise in many applications, ranging from hydro-climatology to finance and insurance. We present fundamental properties of this vector, including marginal and conditional distributions, moments, representations, and parameter estimation. We also include an example from finance, illustrating modeling potential of this new bivariate distribution.     

我国人口老龄化背景下养老产业发展问题研究

在新经济常态背景下,随着人口老龄化程度不断加深,我国财政支出将面临越来越大的挑战,发展养老产业将成为我国应对人口老龄化问题的必然选择。养老产业的发展有利于减轻政府负担,提高老年人生活质量,促进产业调整,缓解就业压力。我国的养老市场规模庞大,并且供不应求,政府高度关注养老产业,为我国大力发展养老产业提供了可行性。但是,尽管目前"保险系""央企系""房企系"等社会资本已经注入,养老产业仍然存在着政府的引导和支持力度不足,缺乏专业人才,相关产业整合难度大,国民养老观念落后等问题。因此,我国应尽快完善相关政策以加强引导和扶持的力度,积极调动社会资源使投资主体多元化,加强养老产业人才队伍建设,加快转变养老观念。     

Reshaping the Social: A Comparison of Fasu and Kubo-Febi Approaches to Incorporating Land Groups

In Papua New Guinea, local communities increasingly strive to render themselves ‘visible’ to the state as entities entitled to control and claim benefits from developments on their land. When people commit expressions of social form to paper they inevitably reshape previously operative social and political forms. This article compares ways in which two groups of Papua New Guineans have gone about the process of forming Incorporated Land Groups. Different histories of resource extraction, associated differences in engagement with state and companies and different pre-existing social forms are all reflected in the negotiations described. We discuss people's motivations for drawing up lists of members, the ways they went about this and implications for the communities themselves and for ILG registration more generally. Our analysis draws attention to how outcomes are shaped by scales of differentiation and emergent inequalities within the legal entities being imagined.     

Water Insecurity: A Case for Social Policy Action by Social Workers

Abstract

This article discusses the nationally and internationally urgent water insecurity issue, and why it represents a highly relevant area for social policy action by social workers, both at local and global levels. Drawing on secondary data analysis, the paper explores the nature and scope of water insecurity as a global social work issue, discusses its social policy dimensions, and suggests a framework for social policy action by social workers. It argues that, due to the complex nature of the water insecurity issue and its consequences, particularly on the poor and disadvantaged groups, and on ecosystems, it is critical to analyse it from conservation, distribution, and access perspectives and to act. Social workers need to think creatively about the application of their knowledge, skills, and virtues to the water insecurity issue in order to bring about necessary changes in human and institutional behaviour relating to water.     

Fetal movement frequency and the effect of associated perinatal factors: Multicenter study

Background

Decreased fetal movements are associated with adverse perinatal outcomes, including stillbirth. Delayed maternal visits to a health care provider after perceiving decreased fetal movements are frequently observed in stillbirths. Informing pregnant women of the normal range of fetal movement frequency is essential in their earlier visits in order to prevent stillbirth.

毛泽东书法在湖南第一师范的影响与传承

通过对湖南第一师范在校学生的现状了解,进行关于毛泽东书法的调查,搜证文献参考资料,着力影响毛泽东书法在湖南第一师范传承,以激发青年学生对书法的热爱与追求。