A generalized model of logistic regression for clustered data

This paper proposes a generalized logistic regression model that can account for the correlation among responses on subunits. The subunits may arise as data on multiple observations within an individual. This method generalizes earlier work by Rosner (1984 a,b) and others. Methodological generalizations include: (1) the use of the more general Polya-Eggenberger distribution instead of the beta-binomial distribution to model the correlation structure, so that cases with negative, positive, or zero intraclass correlation can be handled; (2) a stepwise approach; (3) linear and non-linear regression; and, (4) the inclusion of the case of a truncated distribution. The model can accommodate missing data and covariates on the unit and subunit level. The derivative-free simplex algorithm is used to estimate the parameters.

The model is applied to data describing the progression of obstruction in coronary disease where multiple arterial segments are studied for each patient. The correlation in response that may exist for these multiple segments is accounted for in the analyses while attempting to examine associations with individual-specific (e.g., history of diabetes) and segment-specific (e.g., initial percent stenosis) covariates. Analyses were performed on a data set describing 382 patients with unoperated coronary artery disease and two coronary angiograms separated by at least one month and on a data set describing 284 patients undergoing percutaneous transluminal coronary angioplasty and studied by coronary angiograms.     

Uniform Inference on Quantile Effects under Sharp Regression Discontinuity Designs

ABSTRACT

This study develops methods for conducting uniform inference on quantile treatment effects for sharp regression discontinuity designs. We develop a score test for the treatment significance hypothesis and Wald-type tests for the hypotheses related to treatment significance, homogeneity, and unambiguity. The bias from the nonparametric estimation is studied in detail. In particular, we show that under some conditions, the asymptotic distribution of the score test is unaffected by the bias, without under-smoothing. For situations where the conditions can be restrictive, we incorporate a bias correction into the Wald tests and account for the estimation uncertainty. We also provide a procedure for constructing uniform confidence bands for quantile treatment effects. As an empirical application, we use the proposed methods to study the effect of cash-on-hand on unemployment duration. The results reveal pronounced treatment heterogeneity and also emphasize the importance of considering the long-term unemployed.     

惟玉为葬 惟玉为礼

牛河梁遗址所反映的墓葬形制是墓有中心大墓、大墓、中小型墓、附属墓的等级制.随葬只有玉器,"惟玉为葬",而且中心大墓的葬玉档次高、品质好,数量多.     

铬对海洋生物的影响

铬(Cr)是生物代谢活动中的一个基本营养元素,又是一个很毒的重金属元素。海水中溶解态铬主要以Cr(Ⅲ)、Cr(Ⅵ)和有机铬等形态存在;铬元素在海洋生物体内分布广泛,铬对单细胞藻类有一定的毒害作用,不同种类的单细胞藻类对铬元素有不同程度的富集作用,海洋细菌可将无机铬转化为有机铬;近年来,含铬的饲料已应用于水产养殖业,海洋环境污染研究中也将铬作为监测指标之一。     

论魏晋南北朝散文中的言文矛盾

此文认为中国古代散文的历时性演变中贯穿着言与文的矛盾。散文文体特征的实用性要求它自身的通俗化、质朴化,而早期文学观念的觉醒又制约着散文,使它呈现出绮丽的倾向。魏晋南北朝散文在“文”的主导下,整体而言趋向骈俪化,同时“言”也起着制约的作用,在多数时期处于边缘的位置,但是在某些时候会占据主要地位。     

试述20世纪前期华北乡村中人在社会分层结构中的地位

20世纪前期的华北乡村，由于市场的不完备以及政府职业的不完善，在乡村习惯法中，中人的角色在社会经济运行中是不可或缺的。村庄习俗中，原则上乡村各个阶层的成员均可担当中人，而有乡村秩序运行的具体场景中，中人集中于社区领袖与“能力型”人才两大阶层。但是，二者担任中人的动机与效果有所不同。     

基于艺术教育的民间非物质文化遗产的现代性保护——以云南纸马为例

云南纸马等民间非物质文化遗产，随着社会环境的改变正处于濒危的边缘。本文试图从艺术教育的角度．探索一条有利于云南纸马健康发展的现代性保护之路。     

全球化背景下中国的软实力战略

提高国家文化软实力逐渐成为学界关注的热点问题,十七大以后被提到了国家战略层面。结合部分学者的理论思考,可以将软实力的概念理解为某种形态的文化及其蕴涵的价值观念和意识形态的凝聚力、感染力、吸引力与影响力。文化软实力的提升有助于消解文化冲突,推动综合国力的提升。可以从和谐世界理念推广、社会主义先进文化建设和中华传统文化彰显三个方面着手,构建以文化为核心的中国软实力战略。