Semiparametric regression methods for temporal processes subject to multiple sources of censoring

Process regression methodology is underdeveloped relative to the frequency with which pertinent data arise. In this article, the response-190 is a binary indicator process representing the joint event of being alive and remaining in a specific state. The process is indexed by time (e.g., time since diagnosis) and observed continuously. Data of this sort occur frequently in the study of chronic disease. A general area of application involves a recurrent event with non-negligible duration (e.g., hospitalization and associated length of hospital stay) and subject to a terminating event (e.g., death). We propose a semiparametric multiplicative model for the process version of the probability of being alive and in the (transient) state of interest. Under the proposed methods, the regression parameter is estimated through a procedure that does not require estimating the baseline probability. Unlike the majority of process regression methods, the proposed methods accommodate multiple sources of censoring. In particular, we derive a computationally convenient variant of inverse probability of censoring weighting based on the additive hazards model. We show that the regression parameter estimator is asymptotically normal, and that the baseline probability function estimator converges to a Gaussian process. Simulations demonstrate that our estimators have good finite sample performance. We apply our method to national end-stage liver disease data. The Canadian Journal of Statistics 48: 222–237; 2020 © 2019 Statistical Society of Canada     

大数据背景下网络调查样本的建模推断问题研究——以广义Boosted模型的倾向得分推断为例

随着大数据和网络的不断发展,网络调查越来越广泛,大部分网络调查样本属于非概率样本,难以采用传统的抽样推断理论进行推断,如何解决网络调查样本的推断问题是大数据背景下网络调查发展的迫切需求。本文首次从建模的角度提出了解决该问题的基本思路：一是入样概率的建模推断,可以考虑构建基于机器学习与变量选择的倾向得分模型来估计入样概率推断总体;二是目标变量的建模推断,可以考虑直接对目标变量建立参数、非参数或半参数超总体模型进行估计;三是入样概率与目标变量的双重建模推断,可以考虑进行倾向得分模型与超总体模型的加权估计与混合推断。最后,以基于广义Boosted模型的入样概率建模推断为例演示了具体解决方法。     

China’s flexible overseas food strategy: food trade and agricultural investment between Southeast Asia and China in 1990–2015

Using the UN Comtrade database and multiple sources of agricultural investment data, this paper outlines the emerging patterns of food trade and agricultural investment between Southeast Asian countries and China. The paper shows that China has adopted a flexible overseas food strategy. First, China has increased food export and shifted its food trade with Southeast Asia from a dependent relationship towards a complementary relationship at the regional level in recent years. Second, China tends to adapt to the existing conditions of food production and trade in Southeast Asian countries instead of fundamentally altering them. Finally, Chinese overseas agricultural investment is less driven by domestic food demand but more oriented for profit making, and this gives it flexibility in diversifying investment. An adequate understanding of China’s flexible food strategy in bilateral and multilateral relationships holds implications for global food security.     

Co-Occurring Psychosocial Problems and Multiple Sexual Partners among Men Who Have Sex with Men in Shanghai,China: A Syndemic Approach

We aimed to apply syndemic theory to verify the association and reinforcing effects between psychosocial problems and multiple sexual partners (MSP) of men who have sex with men (MSM) in Shanghai, China. A cross-sectional study was conducted among 547 MSM in Shanghai, China using a face-to-face survey. Sociodemographic and psychosocial data were collected, as well as information on MSP and condomless anal sex. In the 6 months prior to the survey, 54.3% of the MSM sample had had MSP. Univariate analysis showed that self-esteem, depression, loneliness, sexual compulsivity, and involuntary subordination (IS) were associated with MSP. Sexual compulsivity (multivariate odds ratio [ORm] = 2.94, 95% CI = 1.76–4.91) and IS (ORm = 1.79, 95% CI = 1.14–2.81) remained significant in multivariate analysis. MSM with five or more psychosocial problems had greater odds of (adjusted odds ratios = 3.06, 95% CI = 1.49–6.25) having MSP in the previous 6 months than the non-syndemic group. Our findings provide preliminary confirmation of the additive relationship of syndemic psychosocial health conditions and MSP among MSM in Shanghai, China. An integrated intervention with special focus on sexual compulsivity and IS is needed.     

Examining multiplicity and dynamics of publics’ crisis narratives with large-scale Twitter data

The new reality of networked publics on social media calls for crisis communication practitioners and researchers to understand the narratives generated by publics on social media during organizational crises. As social media publics possess diverse, unique characteristics and communicative needs during a crisis, they form interpretative communities and co-create various symbolic interpretations of the crisis. Extending the public-centric and narrative perspective to the context of social media crises, we examined what crisis narratives were constructed by social media publics (i.e., multiplicity) and how these narratives changed by crisis stages (i.e., dynamics). Using topic modelling based on large-scale Twitter data of the Chipotle E. coli crisis (N?=?40,610), we identified ten narratives subsumed under two themes (i.e., sharing-based and conversation-based) based on publics’ social constructions of their perceived risks and crisis experience. On the one hand, sharing-based narratives, heavily impacted by publics’ shared media coverage, reflected media crisis narratives and salient risk perceptions aligning with the news agenda. On the other hand, conversation-based narratives, fueled by publics’ opinion expression and emotional venting, demonstrated publics’ interpretations of their experience with the organization in the crisis with less salient but more diversified risk perceptions. Crisis managers are recommended to produce and deliver compelling narratives resonating with different groups of social media publics during crises.     

理性选择还是社会建构？——欧洲一体化理论范式之争评析

本文追溯了欧洲一体化理论理性选择和社会建构的思想渊源;考察了近年来欧洲一体化研究中理性主义和建构主义在理论和经验层面从论战走向对话的过程;进而以欧盟制宪进程为例分析了社会建构和理性选择机制对这一条约改革过程所具有的解释力及其实现进一步理论融合的潜力.作者认为,这一理论论争表现出搁置元理论层面的分歧,强调理论范式间的通约性,注重问题意识,努力建构超越范式之争的中观理论的特征;这些理论探索也为更广义的国际关系理论发展提供了启示.     

主体伸张文论建构问题的确定及其研究思路

20世纪80年代中期产生的文学主体性理论和近年学界提出的主体间性文学理论这两种知识形态构成了一种理论现象,它们是在主体伸张文学理论建构理路之下文论建构的相当突出的两个环节,对之进行选择性、问题式研究是很有必要的.鉴于这两种理论形态在当代文学理论领域的价值存在,对主体伸张的文论建构问题进行研究也就在一定层面上积极地参与了中国当代文学理论建设问题的思考与探索.     

公共政策视角下的中国人口老龄化

人口老龄化将成为人类社会的常态,它所带来的挑战更多地源于老化的人口年龄结构与现有社会经济体制之间的不协调所产生的矛盾,这使公共政策调节成为必须。仅仅调节人口政策、仅仅调节针对老年人的政策或某一部门的政策都不足以全面应对人口老龄化,而应当以社会整合和长期发展的视角来重构当前的公共政策体系。在重构过程中,不仅要统筹人口系统与其他社会系统的关系,而且要统筹短期目标与中长期战略的联系。因此,应建立一个权威的常态统筹机构,并结合中国的国情,重新定位老年人的社会角色、解决老年人养老的现实问题、支持老龄化社会的可持续发展。     

“土地财政”下的土地和住宅市场:对地方政府行为的分析

在我国当前的分税制财政体制下,地方政府面临着财政和政绩的双重压力。我国目前实行地方政府垄断的土地出让制度,许多受"土地财政"理念主导的地方政府通过一些方式抬高土地出让价格(例如实施"饿地政策"),以弥补预算内收入的不足,缓解财政压力,但是却可能会推动居住用地价格和住宅价格的上涨。更进一步,为了在招商引资中占据优势,许多地方政府压低工业用地价格,抬高居住用地价格以弥补机会成本。本文的实证研究表明,在控制其他因素的情况下,越依赖"土地财政"的城市,以及通过低价出让工业用地进行招商引资力度越强的城市,居住用地供给的受限程度越高,居住用地价格上涨的压力也越大。但上述地方政府行为通过土地市场传导至住宅市场的效果在统计意义上并不显著。     

文化发展的时代特征与河北文化融合创新战略--关于实现我省文化建设新跨越的战略抉择问题

本文从经济全球化、政治多极化、各种文化相互激荡的国际背景,以及我国改革开放的深化和经济社会生活中"四个多样化"新情况的分析中,提炼出文化发展的"四个显著时代特征";概括出我省文化建设上面临的"四个根本转变"的艰巨任务;在此基础上对我省实施文化融合创新战略,实现文化建设新跨越的必要性和紧迫性给以初步论证.