A Note on High-Dimensional Linear Regression With Interactions

The problem of interaction selection in high-dimensional data analysis has recently received much attention. This note aims to address and clarify several fundamental issues in interaction selection for linear regression models, especially when the input dimension p is much larger than the sample size n. We first discuss how to give a formal definition of “importance” for main and interaction effects. Then we focus on two-stage methods, which are computationally attractive for high-dimensional data analysis but thus far have been regarded as heuristic. We revisit the counterexample of Turlach and provide new insight to justify two-stage methods from the theoretical perspective. In the end, we suggest new strategies for interaction selection under the marginality principle and provide some simulation results.     

Statistical measurement of the inventory shortage cost

In searching for the optimal inventory control policy, the objective is to minimize the expected total costs related, of which the shortage cost is an important element. Due to the difficulty in calculating the indirect cost of the loss of goodwill resulted from the shortage, practitioners and researchers often simply assume a fixed penalty cost on the inventory shortage or switch to the alternative method by assigning a specific customer service level. The development of an appropriate tool for measuring the shortage cost can help a business control the total costs and improve the productivity more effectively. This paper proposes probabilistic measurements of the shortage cost, based on mathematical relationship between the cost and the shortage amount. The derived closed-form estimates of the expected shortage cost value can then be applied to support the determination of the optimal inventory control policy.     

Parametric bootstrap inferences for the growth curve models with intraclass correlation structure

This paper presents parametric bootstrap (PB) approaches for hypothesis testing and interval estimation of the fixed effects and the variance component in the growth curve models with intraclass correlation structure. The PB pivot variables are proposed based on the sufficient statistics of the parameters. Some simulation results are presented to compare the performance of the proposed approaches with the generalized inferences. Our studies show that the PB approaches perform satisfactorily for various cell sizes and parameter configurations, and tends to outperform the generalized inferences with respect to the coverage probabilities and powers. The PB approaches not only have almost exact coverage probabilities and Type I error rates, but also have the shorter expected lengths and the higher powers. Furthermore, the PB procedure can be simply carried out by a few simulation steps. Finally, the proposed approaches are illustrated by using a real data example.     

Retrospective change detection in categorical time series

The aim of this paper is to propose methods of detecting change in the coefficients of a multinomial logistic regression model for categorical time series offline. The alternatives to the null hypothesis of stationarity can be either the hypothesis that it is not true, or that there is a temporary change in the sequence. We use the efficient score vector of the partial likelihood function. This has several advantages. First, the alternative value of the parameter does not have to be estimated; hence, we have a procedure that has a simple structure with only one parameter estimation using all available observations. This is in contrast with the generalized likelihood ratio-based change point tests. The efficient score vector is used in various ways. As a vector, its components correspond to the different components of the multinomial logistic regression model’s parameter vector. Using its quadratic form a test can be defined, where the presence of a change in any or all parameters is tested for. If there are too many parameters one can test for any subset while treating the rest as nuisance parameters. Our motivating example is a DNA sequence of four categories, and our test result shows that in the published data the distribution of the four categories is not stationary.     

失地农民健康生活方式测度及其影响因素研究

城镇化在改变了失地农民经济行为的同时,也将导致其生活方式的乡城变迁,其中面向城镇环境的健康生活方式转型对失地农民维系健康水平至关重要.本文从理论层面研究了城镇化背景下失地农民的健康生活方式转型机制及其影响因素;在此基础上,采用规范的健康促进生活方式量表(HPLP)对江苏泰州331个失地农民健康生活方式水平进行实证测度.结果表明,样本地区失地农民健康生活方式总体处于一般状况,其中运动锻炼水平显著不足.进一步运用分位数模型研究发现,相比而言,女性、文化程度较高以及患慢性病的失地农民群体更重视自我健康生活方式的塑造和提升,此外,征地满意度、医疗保险参与率和安置区公共健康服务等外部因素对促进失地农民健康生活方式发展也发挥了积极作用.     

Perceived Need for Home- and Community-Based Services: Experiences of Urban Chinese Older Adults With Functional Impairments

Guided by Cantor’s social care model, this study identified individual, family, and social support factors that influence urban older adults’ need for home- and community-based services, including medical and rehabilitation, instrumental care and support, and psychosocial services. The data were extracted from the Sample Survey on Aged Population in Urban/Rural China conducted by the China Research Center on Aging in 2006. Results from multiple logistic regression show that older adults’ need for medical and rehabilitation services is significantly related to instrumental activities of daily living, depression, not having filial children, friend support networks, and having a confidant. Older adults’ need for instrumental care and support is related to their educational attainment, financial strain, instrumental activities of daily living, not living with children, and friend support networks. Finally, older adults’ need for psychosocial services is significantly related to educational attainment, depression, not being married, friend support networks, and having a confidant. Implications for social service development are discussed.     

东方自由主义传统的发掘——兼评西方话语体系中的“东方专制主义”

长期以来,在西方话语体系中,包括中国在内的东方社会被奴役性、停滞性的"东方专制主义"所定格。然而,改革开放以来的中国崛起的事实,不断挑战这一"千古传奇"和"历史定论"。中国的发展和崛起,并不是源自西方自由主义的进入,而是源自长期被思想界所遮蔽的东方自由主义传统。从主体看,东方中国的自由主义是农民自由主义,核心要素是自由农民的自主性和积极性。这种在自由小农经济基础上产生的农民自由主义作为一种日常生活状态,潜藏于经济社会生活之中,创造了世界无与伦比的农业文明;同时,它也受到专制政体的压制。中国的改革开放起源于对中国数千年以自主性和积极性为核心的农民自由主义传统的尊重,同时又极大地释放了被压抑的自主性和积极性,由此促成了中国的崛起。而在这一过程中,中国特色社会主义制度大大提升了东方自由主义传统,形成具有中国特色的自由体系。     

“村转居”社区的治理模式

"村转居"社区是急速的城市化进程与中国独特的基层社会管理体制相结合的产物,它已成为承接各类新增城市人口的重要空间。在实际的治理过程中,这类社区在居民特征、治理需求、治理资源、治理传统等方面,与原来的农村社区以及成熟的城市社区都有鲜明的差异,因此,其治理模式的选择面临着多种可能性,"自治为主"、"管治为主"和"共治为主"都是可能的选项,其中治理传统的继承水平和社区重建的水平,将在很大程度上决定着"村转居"社区的具体治理模式。     

网络舆情:城市公共安全危机的新症候

作为对现实中的社情民意的复制、重构与超越的网络舆情,作为由民生构成“主体”,民意与民主构成“两翼”的网络舆情,其瞬时到达、瞬间爆发的爆破力越来越触动着城市政府的公共安全神经,越来越幻化为城市公共安全危机的新症侯.城市政府必须超越治理它的认识危机、“他者”化和“硬引导”等问题域,走向科学化、理性化的方法论,即高度重视网络舆情,设置舆情“防火墙”,发挥“主场优势”,确保地方网络成为舆情引导的最短路径,建立“巧引导”范式,形成引导的“网上网下统一战线”,制度化标志性的长效机制等.