A modified random-effect procedure for combining risk difference in sets of 2×2 tables from clinical trials

Summary Meta-analyses of sets of clinical trials often combine risk differences from several 2×2 tables according to a random-effects model. The DerSimonian-Laird random-effects procedure, widely used for estimating the populaton mean risk difference, weights the risk difference from each primary study inversely proportional to an estimate of its variance (the sum of the between-study variance and the conditional within-study variance). Because those weights are not independent of the risk differences, however, the procedure sometimes exhibits bias and unnatural behavior. The present paper proposes a modified weighting scheme that uses the unconditional within-study variance to avoid this source of bias. The modified procedure has variance closer to that available from weighting by ideal weights when such weights are known. We studied the modified procedure in extensive simulation experiments using situations whose parameters resemble those of actual studies in medical research. For comparison we also included two unbiased procedures, the unweighted mean and a sample-size-weighted mean; their relative variability depends on the extent of heterogeneity among the primary studies. An example illustrates the application of the procedures to actual data and the differences among the results. This research was supported by Grant HS 05936 from the Agency for Health Care Policy and Research to Harvard University.     

Generalized Laplacian approximations in Bayesian inference

This paper presents a new Laplacian approximation to the posterior density of η = g(θ). It has a simpler analytical form than that described by Leonard et al. (1989). The approximation derived by Leonard et al. requires a conditional information matrix R_η to be positive definite for every fixed η. However, in many cases, not all R_η are positive definite. In such cases, the computations of their approximations fail, since the approximation cannot be normalized. However, the new approximation may be modified so that the corresponding conditional information matrix can be made positive definite for every fixed η. In addition, a Bayesian procedure for contingency-table model checking is provided. An example of cross-classification between the educational level of a wife and fertility-planning status of couples is used for explanation. Various Laplacian approximations are computed and compared in this example and in an example of public school expenditures in the context of Bayesian analysis of the multiparameter Fisher-Behrens problem.     

Will taxpayers ever like taxes?: Responses to the U.S. Tax Reform Act of 1986

Major policy changes like the 1986 Tax Reform Act (TRA) in the United States provide natural experiments to study attitudinal and behavior responses to law. Surprisingly, public evaluations of the TRA became increasingly negative after passage, while general support for the tax system became more positive in response to the changes. To explain this puzzle, we propose a dynamic model of taxpayer attitudes that is consistent with the observed loose linkage between logically-connected concepts. We briefly review the political context, objectives and impacts of the 1986 Tax Reform Act, and present several studies testing the impact of self-interest, prior beliefs, and social discussion on changes in attitudes and behavior.Results suggest that the complexity of taxes and difficulty in knowing objective impacts weakens the role of self-interest in attitudinal changes, thereby strengthening the role of prior beliefs and discussion. Evaluations of tax laws are most responsive to more politically-oriented influences.     

多目标半无限线性规划的对偶性

本文讨论了多目标半无限线性规划的对偶性，得到了几个重要结论。     

再谈历史心理学

西方心理史学,心态史学和历史心理学的研究目的虽不相同,但都把历史心理现象作为主要研究对象。因此有必要将三者结合创立历史心理学。历史心理学研究历史上个体心理和社会心理及其对历史事件和历史进程的影响。     

资本结构、资本成本理论与资本市场

我国国有上市公司的资本结构存在股权性融资偏好,形成的原因在于市场参考者缺乏资本成本意识,上市公司的经理们不愿承担债务违约和企业破产的风险,上市公司股东监督偏弱。全方位地发展我国多层次资本市场的有效途径是:发展多层次资本市场,尽快培育股民的资本成本意识;发展壮大企业债券市场;完善上市公司的治理结构,加速证券市场的市场化改革;让国有股逐渐流通,建立完善的资本市场机制;有步骤地发展地方性的柜台交易市场和产权市场。     

高校应运用公共关系塑造与传播其外部形象

高校应运用公共关系知识塑造与传播良好的外部形象,创设有利的外部发展环境,以促进自身的健康发展。     

生理学模块教学改革初探

传统教学方法对教师和学生造成束缚,而模块式教学体现了以人为本的教学思想.在生理学理论和实验课的教学过程中,我们采用了模块式教学,尤其在实验教学中,增加了设计性实验模块.模块教学的实施和考核,注重对学生能力的培养,做到学以致用,为学习者提供了思维的空间和实践的新天地,调动了他们的积极性、主动性.     

2004年度国内环境法学研究综述

2004年度国内环境法学研究水平整体有所提高,表现在研究成果比往年明显增多;严谨学风渐长,学界形成良好互动;研究单位不断增加,研究群体逐渐形成规模等方面。研究特点是依然注重基础理论的研究,学界形成争鸣和反思的良好学术风气,关注领域范围扩大等。研究热点包括循环经济法律问题,环境侵权及公益诉讼、环境司法问题,环境刑法问题,国际环境法与国际贸易中的环境问题,自然资源相关法律修改问题等。     

基于顾客资源的动态竞争优势

随着市场竞争环境变化的加剧,企业战略竞争的基点正在从企业内部的资源转移到企业适应外部环境的动态能力上,顾客资源因能有效地衔接企业内部资源和外部环境机会而成为弥足珍贵的战略性资源,以顾客资源为基础构筑的核心竞争力正日益体现出强大的动态竞争优势。因此,企业只有通过加快转变企业的战略管理理念、重构企业内部的业务流程、改革传统的价值链模式和实施企业的顾客忠诚化管理等途径构筑基于顾客资源的动态竞争优势,才能将企业立于竞争的不败之地。