Survival in the U.S. petroleum refining industry

Of the 324 petroleum refineries operating in the U.S. in 1982, only 149 were still in the hands of their original owners in 2007. Using duration analysis, this paper explores why refineries change ownership or shut down. Plants are more likely to ‘survive’ with their original owners if they are older or larger, but less likely if the owner is a major integrated firm, or the refinery is a more technologically complex one. This latter result differs from existing research on the issue. This paper also presents a split population model to relax the general assumption of the duration model that all refiners will eventually close down; the empirical results show that the split population model converges on a standard hazard model; the log-logistic version fits best. Finally, a multinomial logit model is estimated to analyze the factors that influence the refinery plant's choices of staying open, closing, or changing ownership. Plant size, age and technology usage have positive impacts on the likelihood that a refinery will stay open, or change ownership (rather than close down).     

Conditional and marginal estimates in case-control family data – extensions and sensitivity analyses

This work considers two specific estimation techniques for the family-specific proportional hazards model and for the population-averaged proportional hazards model. So far, these two estimation procedures were presented and studied under the gamma frailty distribution mainly because of its simple interpretation and mathematical tractability. Modifications of both procedures for other frailty distributions, such as the inverse Gaussian, positive stable and a specific case of discrete distribution, are presented. By extensive simulations, it is shown that under the family-specific proportional hazards model, the gamma frailty model appears to be robust to frailty distribution mis-specification in both bias and efficiency loss in the marginal parameters. The population-averaged proportional hazards model, is found to be robust under the gamma frailty model mis-specification only under moderate or weak dependency within cluster members.     

命题的本格初探

命题是逻辑哲学的核心概念,许多哲学家提出了自己关于命题本格的观点。弗雷格认为命题即被构造的思想,罗素认为命题是由词项构成的统一体,维特根斯坦认为命题是可能世界的集合。辨析以上观点可以指认:命题是被构造的抽象实体,它是真值载体,独立于自然语言而存在,具有合法的本体论地位。     

从苏童的《妻妾成群》探究中国的女性权力问题

本文分析苏童小说《妻妾成群》,深刻地揭示了女性生存权力的抗争。     

Markets or networks: Households’ choice of financial intermediary in Western China

We argue that households’ choice of financial intermediary is conditioned by households’ social network structures and socioeconomic status. Analyses show that households’ social network size and network composition affect their choices by limiting the quality and quantity of information, resources, and social influence one can access through social ties. Moreover, we find that high-SES families favor formal intermediaries due not only to their richer financial knowledge, higher affordability, and greater capacity to repay loans, but also to their high demands and special types of financial needs that can hardly be satisfied by embedded resources.     

独立学院文化现状及改进对策

大学文化是大学所有成员在历史时间内创造的精神财富和物质财富的总和。而独立学院文化的现状是文化不够鲜明、完整、深厚,因此,独立学院需要从文化培育、文化落实、文化传承、文化创新等方面加以改进。     

A general class of test statistics for Van Valen's Red Queen hypothesis

Van Valen's Red Queen hypothesis states that within a homogeneous taxonomic group the age is statistically independent of the rate of extinction. The case of the Red Queen hypothesis being addressed here is when the homogeneous taxonomic group is a group of similar species. Since Van Valen's work, various statistical approaches have been used to address the relationship between taxon age and the rate of extinction. We propose a general class of test statistics that can be used to test for the effect of age on the rate of extinction. These test statistics allow for a varying background rate of extinction and attempt to remove the effects of other covariates when assessing the effect of age on extinction. No model is assumed for the covariate effects. Instead we control for covariate effects by pairing or grouping together similar species. Simulations are used to compare the power of the statistics. We apply the test statistics to data on Foram extinctions and find that age has a positive effect on the rate of extinction. A derivation of the null distribution of one of the test statistics is provided in the supplementary material.     

Popularity breeds contempt: The evolution of reputational dislike relations and friendships in high school

In this study, we examined the dynamics of the perception of “dislike” ties (reputational dislike) among adolescents within the contexts of friendship, perceived popularity, substance use, and Facebook use. Survey data were collected from a longitudinal sample of 238 adolescents from the 11th and 12th grades in one California high school. We estimated stochastic actor-based network dynamic models, using reports of reputational dislike, friendships, and perceived popularity, to identify factors associated with the maintenance and generation reputational dislike ties. The results showed that high-status adolescents and more frequent Facebook users tended to become perceived as or stay disliked by their peers over time. There was a tendency for friendships to promote the creation and maintenance of reputational disliking but not vice versa. Adolescents tended to perceive others as disliked when their friends also perceived them as disliked. There was no evidence that either cigarette smoking or drinking alcohol affected reputational dislike dynamics. This study highlights the important role that the hierarchical peer system, online peer context, and friendships play in driving information diffusion of negative peer relations among adolescents.     

Family Formation and Close Social Ties Within Religious Congregations

The study of family and religion has yet to elaborate on the social ties that connect these two important and changing institutions. Specifically, how does family formation (i.e., marriage and childrearing) impact social ties to religious communities? Using longitudinal data from the Portraits of American Life Study (2006–2012) and fixed effects regression models that control for time‐stable heterogeneity (N = 1,314), this study tests the effects of marriage and childrearing on changes in close congregational social ties. Fixed effects estimates suggest that marriage actually decreases close social ties to religious congregations, whereas rearing children within marital unions increases them. Thus, it is children, not marriage per se, that actually integrates married couples into religious communities. These contrasting effects tend to be the strongest among young adults, but they weaken with age as well as marital duration.