Nonparametric Shrinkage Estimation for Aalen's Additive Hazards Model

Aalen's nonparametric additive model in which the regression coefficients are assumed to be unspecified functions of time is a flexible alternative to Cox's proportional hazards model when the proportionality assumption is in doubt. In this paper, we incorporate a general linear hypothesis into the estimation of the time‐varying regression coefficients. We combine unrestricted least squares estimators and estimators that are restricted by the linear hypothesis and produce James‐Stein‐type shrinkage estimators of the regression coefficients. We develop the asymptotic joint distribution of such restricted and unrestricted estimators and use this to study the relative performance of the proposed estimators via their integrated asymptotic distributional risks. We conduct Monte Carlo simulations to examine the relative performance of the estimators in terms of their integrated mean square errors. We also compare the performance of the proposed estimators with a recently devised LASSO estimator as well as with ridge‐type estimators both via simulations and data on the survival of primary billiary cirhosis patients.     

The use of vignettes to empower effective responses to attempted sexual assault

Objective: Women assertively resisting sexual aggression have the best chances of avoiding completed rape. Especially with acquaintances, there are significant social and psychological barriers to resistance. Novel vignettes depicting acquaintance rape were designed to enhance self-efficacy, reduce unrealistic optimism, and empower assertive resistance. Participants: The data were collected using a Web-based survey of 449 female college students from multiple universities in August–October 2014. Methods: Between-subjects mixed-methods design. Participants were randomly assigned to read one of four vignettes and complete self-report measures of personal vulnerability, self-efficacy, and beliefs and intention about resistance. Results: Although vignettes did not impact self-efficacy, one vignette enhanced perceived controllability and decreased unrealistic optimism. Women who read about completed acquaintance rape described intention to use physically assertive responses at double the rate of women reading about successful resistance. Conclusions: As low-cost, easily disseminated materials, vignettes about sexual assault may enhance campus prevention efforts.     

“Service” Municipal Administration as Part of the Development of Youth Entrepreneurship in Russia

The study offers a development of the social technologies of “service” municipal administration. The consumers’ opinions should be taken into consideration when determining the nomenclature and standards of their provision, which include the quality parameters that the consumers consider important. In addition, “service” relations imply the assessment of consumer satisfaction with the services and the correction of services based on the results of the assessment. Since this interaction implies communication between the municipal administration body and service users, it is necessary to focus on communicative technologies that are capable of providing a full cycle of service development and improvement for young entrepreneurs. Communications should help determine the expectations associated with a service, raise awareness thereof, and involve young people in the decisions related to the provision of services.     

社交网络个体活跃行为的大数据分析：从网络外部性的视角

用户是社交网络平台的基石，用户的活跃行为为平台创造内容、带来价值，因而用户活跃度一直是社交网络平台的关注重点。已有研究仅关注用户是否存在持续使用意向或行为，将持续使用行为定义为二元变量，未对持续使用行为细分，忽略了对用户活跃行为的研究。此外，社交网络中用户活跃行为之间有着不可忽视的相互影响，而受制于用户的关系网络数据难以获取，少有研究从该角度对社交网络中的用户行为进行研究。 将持续使用行为进一步细分为个体活跃和沉默行为，从网络外部性视角探讨同伴活跃行为对焦点个体活跃行为的影响以及个体网络规模与活跃行为的关系，并进一步探讨个体间关系强度和个体特征的调节作用。以超过百万用户的真实关系网络、个体特征信息和使用行为数据进行实证分析，通过Tobit模型验证上述关系。 研究结果表明，同伴活跃度和个体网络规模对个体活跃度有显著的正向作用，同时关系强度具有正向调节作用；个体特征在同伴活跃度与个体活跃度之间起调节作用，具体来说，女性用户和年轻用户受同伴活跃行为的影响更强。 从网络外部性的角度探讨用户活跃行为的影响因素，拓展了关于在线社交网络用户持续使用行为的研究和网络外部性测量方式，关注不同节点对于网络外部性贡献的差异性，对今后网络外部性的研究有一定的借鉴意义。基于中国数百万真实用户的数据集，结果更具普适性，同时反映出中国在线社交网络中用户的行为特征，可为今后的研究者提供参考。研究结果可以帮助社交网络平台的管理者更加了解用户活跃度的影响机理以及用户行为之间的内在联系，从而能以更科学合理的方式激发用户活跃度，保持社交网络平台的持续运营。     

A Theory of Time Preference

This article proposes that people generally prefer present consumption to future consumption because their expected utility from consumption (eventually) falls as their mental and physical abilities (eventually) decline with age. Moreover, contrary to the ubiquitous intertemporal formulation with a constant rate of time preference and contrary to three recent theories of time preference that predict decreasing discounting as people age, this article asserts that discounting increases over the life cycle. This hypothesis is supported by data from the Panel Study of Income Dynamics as well as evidence from numerous previous studies.     

Is a Reasonable Attempt Reasonable? Shaping Versus Reinforcing Verbal Attempts of Preschoolers with Autism

The effectiveness of a language-training procedure that emphasized reinforcing vocal “reasonable attempts” (any response directed at an interventionist and within a broader class of correct responses) was compared with a procedure that emphasized shaping (reinforcing successive approximations that more closely resembled the target vocalization). Three preschoolers who had been diagnosed with autism spectrum disorders participated in the study. Data indicated that the children mastered vocal skills more rapidly when they learned through shaping than in the reasonable attempts condition. Implications for teaching children with autism spectrum disorders are discussed.     

‘Dirty Work?’ Gender,Race and the Union in Industrial Cleaning

The study uses an eclectic framework and through an intersectional analysis and use of narratives explores the meaning of janitorial work, the gender division of labour (GDL), the unions and organizing for janitors engaged in industrial cleaning for a big cleaning company, Pluto, in Toronto. Pluto was organized by the Service Employees International Union (SEIU) in 2006. The study is based on the organizing drive for Pluto and uses participant observation and interview methods. Intersectional analysis is useful in understanding the worker's perceptions of the racialized, gendered and classed constitution of cleaning work as ‘dirty’ and their resistance to these constructs. We explore GDL in industrial cleaning and the construction of women's work as ‘light duty’ and men's work as ‘heavy duty’. We conclude that union membership is important not only for material benefits of the janitors but also for their alternative identity construction. However, there is a persistence of GDL and gender pay equity is not addressed seriously in the organizing drive or upon organizing.     

‘Business under new management’ — lessons from Canada on regulation of the social work profession

Abstract

In December 1998 the Social Work and Social Service Work Act (hereafter the Ontario Act) was passed in Ontario, Canada marking the effective completion of social work regulatory legislation across provincial Canada. This article outlines the principal features of the Ontario regulations, and summarises the strengths and limitations of the various arrangements which have been implemented across Canada. As moves toward control of the Australian social work profession are contemplated, the implications for such a move are discussed in the light of the Canadian experience.     

Exact and approximate distributions for linear contrasts of means and variances

A Bayesian analysis is presented for the K-group Behrens-Fisher problem. Both exact posterior distributions and approximations were developed for both a general linear contrast of the K means and the K variances, given either proper diffuse or informative conjugate priors. The contrast of variances is a unique feature of the heterogeneous variance model that enables investigators to test specific effects of experimental manipulations on variance. Finally, important-differences were observed between the heterogeneous variance model and the homogeneous model.