Efficient Inference for Longitudinal Data Varying‐coefficient Regression Models

Informative identification of the within‐subject correlation is essential in longitudinal studies in order to forecast the trajectory of each subject and improve the validity of inferences. In this paper, we fit this correlation structure by employing a time adaptive autoregressive error process. Such a process can automatically accommodate irregular and possibly subject‐specific observations. Based on the fitted correlation structure, we propose an efficient two‐stage estimator of the unknown coefficient functions by using a local polynomial approximation. This procedure does not involve within‐subject covariance matrices and hence circumvents the instability of calculating their inverses. The asymptotic normality of resulting estimators is established. Numerical experiments were conducted to check the finite sample performance of our method and an example of an application involving a set of medical data is also illustrated.     

对明初重刑主义的再思考

在中国的历来的历史上,重刑政策做为镇压人民,维护王朝专制统治的重要手段,为古来不少封建王朝所使用,但要伦用法之严、用刑之广,杀戮之盛,首屈一指的要属明初了.但是明初的重刑并未使得社会安定,相反得是犯罪率的高频发和人民的不断反抗.所以我们要对明初重刑主义的错误进行反思,纠正我国在立法和司法实践中的重刑倾向,使得在社会中刑法的作用能真正表现出来.     

Bayesian sample size determination for phase IIA clinical trials using historical data and semi‐parametric prior's elicitation

The Simon's two‐stage design is the most commonly applied among multi‐stage designs in phase IIA clinical trials. It combines the sample sizes at the two stages in order to minimize either the expected or the maximum sample size. When the uncertainty about pre‐trial beliefs on the expected or desired response rate is high, a Bayesian alternative should be considered since it allows to deal with the entire distribution of the parameter of interest in a more natural way. In this setting, a crucial issue is how to construct a distribution from the available summaries to use as a clinical prior in a Bayesian design. In this work, we explore the Bayesian counterparts of the Simon's two‐stage design based on the predictive version of the single threshold design. This design requires specifying two prior distributions: the analysis prior, which is used to compute the posterior probabilities, and the design prior, which is employed to obtain the prior predictive distribution. While the usual approach is to build beta priors for carrying out a conjugate analysis, we derived both the analysis and the design distributions through linear combinations of B‐splines. The motivating example is the planning of the phase IIA two‐stage trial on anti‐HER2 DNA vaccine in breast cancer, where initial beliefs formed from elicited experts' opinions and historical data showed a high level of uncertainty. In a sample size determination problem, the impact of different priors is evaluated.     

我国不同性质企业技术创新效率及其影响因素研究:基于两阶段价值链的视角

本文从价值链角度出发,构建关联型两阶段DEA模型,测度和比较2005-2010年中国不同性质工业企业、内资等3类企业的科技研发和成果转化效率及差异,给出创新资源利用的4种模式,并利用Tobit模型检验了效率的影响因素。研究表明:(1)考察期内工业企业创新整体效率均值为0.694,科技研发和成果转化阶段效率偏低成为制约效率提升的共同因素。(2)中国内资、港澳台商投资企业和外商投资企业创新效率依次递增,效率差异明显。国有或国有控股企业由于创新剩余控制权和索取权的分离,缺乏有效的创新激励和监督。而外资企业利用母国技术、品牌等优势,在科技成果转化领域较为成功。属于高研发高转化的企业仅占33.3%,主要来自港澳台商和外资企业。(3)企业规模的壮大有利于科技研发效率的提升,而科学家和工程师数与科技研发效率负相关。企业规模对科技成果转化效率和整体效率具有显著正向影响,政府支持和金融支持则对二者有明显负作用。最后,给出了一些政策建议。     

Competition and Coordination in Two‐Tier Public Service Systems under Government Fiscal Policy

As a result of government budgetary limits and rapid market growth, many public service systems—such as health care—are characterized by extensive customer wait times that have become a serious problem. This problem might be solved by allowing private firms to enter these markets, which would provide customers with a choice between a free (governmental) public service provider (SP) and a fee‐charging (or “toll”) private SP. In such a two‐tier service system, the two SPs are differentiated by service quality and cost efficiency. This study focuses on the competition and coordination issues for two‐tier service systems with customers who are sensitive to both service quality and delay. The free system attempts to maximize its expected total customer utility with limited capacity, whereas the toll system attempts to maximize its profit. Neither goal is aligned with the social welfare goal of the public service. To achieve the social welfare goal, the government plays a crucial role in coordinating the two‐tier service system via the budget, the tradeoff of social members' goals, and tax‐subsidy policies. Using a mixed duopoly game, we establish Nash equilibrium strategies and identify the conditions for the existence of the two‐tier service system. We employ several interesting and counter‐intuitive managerial insights generated by the model to show that the public service can be delivered more efficiently via customer choice and SP competition. In addition, we show that a relatively low tax‐subsidy rate can almost perfectly coordinate the two SPs to achieve most of the maximum possible benefit of the two‐tier service system.     

中国特色社会主义理论体系的内在逻辑

中国特色社会主义理论体系的形成是中国共产党“以俄为师”、“以祖为师”、“以美为师”三条路线相结合的产物。它的产生依据是：防止过“左”的逻辑,以消除对前苏联结局的“隐喻”性担忧;防止复“古”的逻辑,以减少官僚传统及其“影子”对现实的干扰;防止过“右”的逻辑,以驱散将普世价值“过度引伸”导致的迷障。     

历史制度主义视域的农村五保供养制度变迁研究

从历史制度主义的理论视域看,我国农村五保供养制度结构受到宏观历史情境、变量及其他政策序列、行为主体博弈互动关系的影响和制约;同时我国农村五保供养制度的历史变迁具有路径依赖和渐进转型的特性,存在关键节点并呈现为断裂平衡的过程。我国农村五保供养应打破"历史否决点"并适应新的制度环境,不断推动制度的创新。     

高校开放办学的价值、内涵与策略

开放办学是经济社会发展的现实需求,是高等教育发展的基本规律,也是高校内涵建设的必然选择。开放办学核心在于区域协同和国际合作,关键在于开放理念的树立以及机制和平台的构建。开放办学在“一体两翼”的框架下,要坚持遵循从被动服务走向主动合作,从配合研究走向协同创新,从单边合作走向双边互惠,从容纳吸收走向交流融合的行动策略。     

Precise large deviations for the difference of two sums of END random variables with heavy tails

Assume that there are two types of insurance contracts in an insurance company, and the ith related claims are denoted by {X_ij, j ? 1}, i = 1, 2. In this article, the asymptotic behaviors of precise large deviations for non random difference ∑^n₁(t)_{j = 1}X_1j ? ∑^n₂(t)_{j = 1}X_2j and random difference ∑^N₁(t)_{j = 1}X_1j ? ∑^N₂(t)_{j = 1}X_2j are investigated, and under several assumptions, some corresponding asymptotic formulas are obtained.