Multivariate Kendall's tau for change‐point detection in copulas

Statistical procedures for the detection of a change in the dependence structure of a series of multivariate observations are studied in this work. The test statistics that are proposed are $L_1$ , $L_2$ , and $L_{\infty }$ distances computed from vectors of differences of Kendall's tau; two multivariate extensions of Kendall's measure of association are used. Since the distributions of these statistics under the null hypothesis of no change depend on the unknown underlying copula of the vectors, a procedure based on the multiplier central limit theorem is used for the computation of p‐values; the method is shown to be valid both asymptotically and for moderate sample sizes. Alternative versions of the tests that take into account possible breakpoints in the marginal distributions are also investigated. Monte Carlo simulations show that the tests are powerful under many scenarios of change‐point. In addition, two estimators of the time of change are proposed and their efficiency is carefully studied. The methodologies are illustrated on simulated series from the Canadian Regional Climate Model. The Canadian Journal of Statistics 41: 65–82; 2013 © 2012 Statistical Society of Canada     

长期外出流动人口的养老境遇:基于停留预期与社保参与状况的分析

流动人口的社会保障问题一直以来备受社会各界的广泛关注。本文运用国家人口计生委2010年实施的106个城市流动人口监测调查数据,对停留在流入城市达10年及以上的流动人口这一最先迈入老龄阶段的群体,就其人口社会特征和停留预期与养老境遇进行重点分析。总体而言,长期外出流动人口显示有长期停留之预期,但社会保险的参与状况却令人堪忧。此外,不同人口社会特征的长期外出流动人口,其长期停留预期和社保参与状况存在一定差别。     

在应对“用工荒”中推动企业转型升级

总结用工荒的基本特征,分析其产生的原因,并提出企业和政府联手应对用工荒的对策。认为企业要通过机械化和自动化降低用工依赖、提高效率和向低成本地区转移来化解用工高成本,变革企业管理减少员工流失。政府要通过加快区域产业布局调整、加强农民工职业技能培训、加快农业现代化建设提高用工供给、推动农民工与市民在住房保障等方面平权、优化农民工就业服务和劳动力市场建设、构建少取多予的财税扶持等措施,帮助企业应对用工荒,实现转型升级。     

Shared and unique characteristics of school,cyber and family victimization among school-aged children in Hong Kong

Victimizations from online and offline violence, such as sibling violence, school violence and witness of family violence, both have negative associations with victims' mental health and may share similar individual and family characteristics. This study aims to explore the common and differentiated characteristics in the prediction of school, cyber and family victimization and whether there are unique associations within these victimization types. We employed a two-stage stratified sampling method to collect a representative sample of 5567 children aged 3–17 from a cross-sectional, school-based survey in Hong Kong. Results showed that all types of child victimization, including sibling, school and cyberbullying, as well as the witness of violence at home, were positively correlated with each other. Children's age was positively related to the occurrence and cooccurrence of all types of child victimization. Frequent family residential mobility and parents' higher education level were positively related to all types of children's victimization. The scores of all aspects of children's paediatric quality of life were found negatively related to children's school victimization. This study provides insight into the unique and shared elements of children's online and offline victimization. Knowledge of the distinguished familial gradients of child victimization at home and beyond could benefit the development of child victimization prevention.     

Crafting the Neoliberal State: Workfare,Prisonfare, and Social Insecurity1

In Punishing the Poor, I show that the ascent of the penal state in the United States and other advanced societies over the past quarter‐century is a response to rising social insecurity, not criminal insecurity; that changes in welfare and justice policies are interlinked, as restrictive “workfare” and expansive “prisonfare” are coupled into a single organizational contraption to discipline the precarious fractions of the postindustrial working class; and that a diligent carceral system is not a deviation from, but a constituent component of, the neoliberal Leviathan. In this article, I draw out the theoretical implications of this diagnosis of the emerging government of social insecurity. I deploy Bourdieu’s concept of “bureaucratic field” to revise Piven and Cloward’s classic thesis on the regulation of poverty via public assistance, and contrast the model of penalization as technique for the management of urban marginality to Michel Foucault’s vision of the “disciplinary society,” David Garland’s account of the “culture of control,” and David Harvey’s characterization of neoliberal politics. Against the thin economic conception of neoliberalism as market rule, I propose a thick sociological specification entailing supervisory workfare, a proactive penal state, and the cultural trope of “individual responsibility.” This suggests that we must theorize the prison not as a technical implement for law enforcement, but as a core political capacity whose selective and aggressive deployment in the lower regions of social space violates the ideals of democratic citizenship.     

中国城镇职工性别工资差距的演变(英文)

本文利用1995年、2002年和2007年的数据,分析了城镇工资的性别差距的演变特点和影响因素。研究结果表明,1995--2007年特别是2002--2007年期间工资的性别差距显著扩大,其中不可解释部分的比例也越来越大,显示了性别歧视的严重化问题。年纪轻、学历低、职业差、行业差的女性职工在劳动力市场中受到更为严重的歧视,导致了低收入群体性别工资差距的迅速扩大。     

SPECIAL ISSUE： INCOME INEQUALITY IN CHINA High Incomes in Monopoly Industries： A Discussion

本文应用Oaxaca-Blinder分解方法,把垄断行业高收入分解为合理和不合理两个部分。实证分析发现,垄断行业与竞争行业之间收入差距的50％以上是不合理的。这主要是行业的垄断造成的。由于目前收入统计未能反映垄断行业的高福利,以上测量结果显然低估了垄断行业高收入中的不合理部分。     

Are Overall Journal Rankings a Good Mapping for Article Quality in Specialty Fields?

Overall journal rankings, which are generated with sample articles in different research fields, are commonly used to measure the research productivity of academic economists. In this article, we investigate a growing concern in the profession that the use of the overall journal rankings to evaluate scholars’ relative research productivity may exhibit a downward bias toward researchers in some specialty fields if their respective field journals are under-ranked in the overall journals rankings. To address this concern, we constructed new journal rankings based on the intellectual influence of research in 8 specialty fields using a sample consisting of 26,401 articles published across 60 economics journals from 1998 to 2007. We made various comparisons between the newly constructed journal rankings in specialty fields and the traditional overall journal ranking. Our results show that the overall journal ranking provides a considerably good mapping for the article quality in specialty fields. Supplementary materials for this article are available online.     

Estimating the prevalence of low-lumbar spine bone mineral density in older men with or at risk for HIV infection using normal mixture models

Bone mineral density decreases naturally as we age because existing bone tissue is reabsorbed by the body faster than new bone tissue is synthesized. When this occurs, bones lose calcium and other minerals. What is normal bone mineral density for men 50 years and older? Suitable diagnostic cutoff values for men are less well defined than for women. In this paper, we propose using normal mixture models to estimate the prevalence of low-lumbar spine bone mineral density in men 50 years and older with or at risk for human immunodeficiency virus infection when normal values of bone mineral density are not generally known. The Box–Cox power transformation is used to determine which transformation best suits normal mixture distributions. Parametric bootstrap tests are used to determine the number of mixture components and to determine whether the mixture components are homoscedastic or heteroscedastic.