Alternative estimation methods for identifying contagion effects in dynamic social networks: A latent-space adjusted approach

Contagion effects, also known as peer effects or social influence process, have become more and more central to social science, especially with the availability of longitudinal social network data. However, contagion effects are usually difficult to identify, as they are often entangled with other factors, such as homophily in the selection process, the individual’s preference for the same social settings, etc. Methods currently available either do not solve these problems or require strong assumptions. Following Shalizi and Thomas (2011), I frame this difficulty as an omitted variable bias problem, and I propose several alternative estimation methods that have potentials to correctly identify contagion effects when there is an unobserved trait that co-determines the influence and the selection. The Monte-Carlo simulation results suggest that a latent-space adjusted estimator is especially promising. It outperforms other estimators that are traditionally used to deal with the unobserved variables, including a structural equation based estimator and an instrumental variable estimator.     

高校“大学生机会型创业”教育体系研究——以浙江省为例

本文在分析机会型创业推进模型和创业外部环境因素的基础上,提出了构建高校大学生机会型创业教育矩阵模型,并对完善我国高校大学生机会型创业教育教学提出建议和对策。     

Work-family culture and job satisfaction: does gender and parenting status alter the relationship?

Previous studies on work-family culture have examined its relationship with different employee outcomes (e.g., work-family conflict, job satisfaction, commitment) but neglected one important question; namely, who are most likely to benefit from a supportive work-family culture in terms of positive employee outcomes? The aim of this study was to shed new light on the work-family culture–job satisfaction linkage by examining the moderator effects of gender and parenting status in this relationship. Specifically, we asked whether gender and parenting status would alter the association between work-family culture and job satisfaction. We hypothesized – on the basis of traditional gender roles – that women, and especially mothers, would benefit most from a family supportive organizational culture. We utilized three divergent samples gathered from male (N=768) and female (N=1364) employees in Finland: (1) a female-dominated sample from social and health care; (2) a male-dominated sample from paper industry; and (3) more gender-mixed sample from the ICT company. Work-family culture was described through its positive (work-family support) and negative facets (work-family barriers), whereas job satisfaction was operationalized via a facet-based scale. Hierarchical moderated regression analyses performed separately for the three different organizations revealed that the results for mothers and fathers under the condition of high work-family support differed in the paper mill and the information and communication technology (ICT) company. Thus, in addition to gender, the type of organization also moderated the relationship. Specifically, in the paper mill, mothers benefited more from high work-family support than fathers, whereas in the ICT company the reverse situation held: fathers benefited more than mothers. Thus, high work-family support was associated with higher job satisfaction among mothers in the paper mill and among fathers in the ICT company.     

网络传播中“情绪对应”现象与效应分析——基于《今日头条》样本数据的实证挖掘

基于网络传播大数据的实证分析显示,“情绪对应”不仅是一种整体意义上的强效果论,而且还在相当大的程度上体现出鲜明的甚至可预测的作用关系。分别从标题情绪促发的评论情绪的概率矩阵、评论情绪回溯的标题情绪概率矩阵进行分析。实证考察的详细结果显示：各种情绪的帖子和评论在绝对比重和相对比重上,都显现出相同情绪之间的对应和对称。情绪在网络“意见”和“议程”等内容传播层面需突出其系统性涉及的本体地位,加强从“信息的内容”向“信息的形式”的延展,强调情绪形式及其关系中的主体间性和传受间性。     

Evolution of product quality in European,Japanese and US automotive firms: An exploratory longitudinal analysis

For years we have been hearing that US automobile manufacturers have been losing market share to their Japanese rivals who are reputed to make better quality vehicles. Most such reports are based on the initial quality surveys on new automobiles. In this paper we address two exploratory questions: (1) how does the quality of an automobile change with its age, and, (2) can firm level variables help explain differences quality. To answer these questions, we collected Consumer Reports’ reliability ratings on approximately 300 automobile models made by European, Japanese and US automotive firms during the 1998–2007; and approximately 240 models made by these firms over period of 2008–2015. For both periods we found that not only do automobiles made by Japanese firms have higher initial quality, but, as automobiles get older the difference in the product quality between Japanese versus European and US firms increases. We also found that the more generalist a European or US automobile firm, i.e., the wider is the firm׳s product offering in the marketplace, the lower its overall automobile quality during the 1998–2007 period. Conversely, Japanese generalist firms were found to have higher quality than specialist firms over the same period. The result is partly explained by the fact that Japanese firms have taken a different path to broadening their product variety – they have ensured a high level of quality of their initial offerings before entering newer market segments. The rate of reliability decline was found to be slower for all firms, and the differences in reliability across the 3 groups of firms were much less pronounced during the 2008–2015 period. This improvement may be as result of restructuring done by US automobile firms.     

Enabling robust assessment of QTc prolongation in early phase clinical trials

Since the implementation of the International Conference on Harmonization (ICH) E14 guideline in 2005, regulators have required a “thorough QTc” (TQT) study for evaluating the effects of investigational drugs on delayed cardiac repolarization as manifested by a prolonged QTc interval. However, TQT studies have increasingly been viewed unfavorably because of their low cost effectiveness. Several researchers have noted that a robust drug concentration‐QTc (conc‐QTc) modeling assessment in early phase development should, in most cases, obviate the need for a subsequent TQT study. In December 2015, ICH released an “E14 Q&As (R3)” document supporting the use of conc‐QTc modeling for regulatory decisions. In this article, we propose a simple improvement of two popular conc‐QTc assessment methods for typical first‐in‐human crossover‐like single ascending dose clinical pharmacology trials. The improvement is achieved, in part, by leveraging routinely encountered (and expected) intrasubject correlation patterns encountered in such trials. A real example involving a single ascending dose and corresponding TQT trial, along with results from a simulation study, illustrate the strong performance of the proposed method. The improved conc‐QTc assessment will further enable highly reliable go/no‐go decisions in early phase clinical development and deliver results that support subsequent TQT study waivers by regulators.     

应当强调办案的社会效果

法律的概括性、抽象性、发展性等特点决定了有必要强调办案的社会效果。强调办案的社会效果有利于制约司法自由裁量权,是新时期司法工作的必然要求。     

Racial diversity, minority concentration, and trust in Canadian urban neighborhoods

Using a sample of 42,329 respondents nested within 4254 Canadian urban neighborhoods, this study demonstrates the conceptual and empirical importance of making a distinction between neighborhood racial diversity and minority concentration, and examines how each is uniquely associated with trust. Our analysis shows that at a given level of racial minority concentration, Whites are more trusting when their minority neighbors are more evenly distributed across racial minority groups. Meanwhile, Whites are less trusting as the neighborhood share of racial minorities increases. Overall, the effect of racial minority concentration tends to prevail over that of racial diversity.     

Deconvolution methods for non-parametric inference in two-level mixed models

Summary.  We develop a general non-parametric approach to the analysis of clustered data via random effects. Assuming only that the link function is known, the regression functions and the distributions of both cluster means and observation errors are treated non-parametrically. Our argument proceeds by viewing the observation error at the cluster mean level as though it were a measurement error in an errors-in-variables problem, and using a deconvolution argument to access the distribution of the cluster mean. A Fourier deconvolution approach could be used if the distribution of the error-in-variables were known. In practice it is unknown, of course, but it can be estimated from repeated measurements, and in this way deconvolution can be achieved in an approximate sense. This argument might be interpreted as implying that large numbers of replicates are necessary for each cluster mean distribution, but that is not so; we avoid this requirement by incorporating statistical smoothing over values of nearby explanatory variables. Empirical rules are developed for the choice of smoothing parameter. Numerical simulations, and an application to real data, demonstrate small sample performance for this package of methodology. We also develop theory establishing statistical consistency.     

论传统节日的衰落:从时空设置的角度

作为一种重要的"时空设置",节日体现的是集体生活的节奏和规律.当前中国的节日体系中,政治性节日缺少文化内涵和礼仪行为,宗教性节日缺少意识形态合法性,而传统的时令性节日已经在现代生活面前失去原有的地位.要想节日既传达出传统的文化价值,又能够促进社会各层次多方面的和谐发展,必须寻找到社会生活的整体节奏,并在节日的设置方面体现这一节奏.