Implications of survey design for generalized regression estimation of linear functions

The paper presents a general randomization theory approach to point and interval estimation of Q linear functions T_q = Σ^N₁c_kqY_k(q = 1,…,Q), where Y₁,…,Y_N are values of a variable of interest Y in a finite population. Such linear functions include population and domain means and totals, population regression coefficients, etc. We assume that some auxiliary information can be exploited. This suggests the generalized regression technique based on the fit of a linear model, whereby is created approximately design unbiased estimators T?_q. The paper focuses on estimation of the variance-covariance matrix of the T?_q for single stage and two stage designs. Two techniques based on Taylor expansions are compared. Results of Monte-Carlo experiments (not reported here) show that the coverage properties are good of normal-theory confidence intervals flowing from one or the other variance estimate.     

The Role of Joint Attention in Later Development Among Preterm Children: Linkages Between Early and Middle Childhood

Joint attention is a hallmark of human cognition. It refers to the capacity to coordinate attention to objects and events with attention to other people. Infants display considerable individual differences in this capacity. This longitudinal study of 13‐month‐old preterms was conducted to examine the hypothesis that two different types of joint‐attention skills assessed in an infant–tester paradigm are related to verbal and nonverbal IQ measures through middle childhood. Data are reported separately for the children's tendency to initiate such skills and to respond to an experimenter's offers to share in such behaviours. The results provide support for the hypothesis that the initiation of joint attention makes a unique contribution to later nonverbal IQ apart from variance associated with biomedical risk status and infant development. The results of this study have implications for the conceptualisation of joint‐attention skills, as well as for understanding the relation between joint attention and later cognition.     

HIV-infected African families living in Stockholm/Sweden: their social network, level of disclosure and knowledge about HIV

Most HIV-infected parents in Stockholm are of African origin. Many of them have several children, but their social network is often limited. This article looks at the networks of these families in relation to different aspects of HIV in order to improve the support strategies. The theoretical basis of the study rests on network and ecological systems theory. The social networks of the families in the study were found to be generally of similar size in Sweden and in the home country. However, of 47 HIV-infected parents only 21 (45%) had disclosed their HIV status to friends and relatives in Sweden. The lack of a social network was especially prominent among single women. Contact with counsellors at the HIV clinic and the social welfare office increased the probability of disclosure about HIV infection. The lack of knowledge about HIV transmission and about whom to inform about the infection stresses the importance of improved counselling. The support strategies aimed at broadening the patient's network and breaking their isolation need to be continued and strengthened.     

The Role of Forgiveness in Divorce Adjustment and the Impact of Affect

The role of forgiveness and affect was investigated in relation to divorce adjustment. Ninety-one participants separated from their ex-spouse less than 30 months completed a background questionnaire, the Enright Forgiveness Inventory (EFI), the Self Forgiveness Scale (SFS), the Center for Epidemiological Studies–Depression Inventory (CES–D), the Spielberger State–Trait Anger Inventory (STAXI–2), and the Fisher Divorce Adjustment Scale (FDAS). There were significant relationships between depression and the capacity to forgive and between being in an angry feeling state and harboring a lack of forgiveness toward the ex-spouse. The relationship that emerged as the most powerful was that between trait anger and lack of self-forgiveness. Forgiveness intervention that occurs early in the divorce adjustment process is implicated, particularly in relation to the self.     

旅游研究中的“真实性”:纷争之后

真实性的内涵如此多义,以致莱辛格与斯坦纳提出应摒弃该概念。然而自麦坎内尔将真实性引入社会学研究的30年来,相关研究蔚为大观,学界就客观真实性、主观真实性与建构真实性展开系列辩论与研究;另一方面,实践中的真实性样态层出不穷,譬如真实的复制与真正的赝品、生命历程中的真实性或人造景观的真实性。在后真实时代,旅游客体的真实性主要由旅游体验来裁决。     

From exile to post-exile: the diasporisation of Swedish Chileans in historical contexts

The main focus of this article is how a set of practices revolve around the formation of an imagined community in dispersion – diasporisation. The study discusses the case of the Chilean diaspora in Sweden and its transformation from an exile context to a post-exile context facing a drastically altered historical situation. This transformation is analysed as a matter of agency where practices are framed differently as a response to the demand perceived in the context. The outcome of this argument speaks in favour of a diaspora concept that focuses on practices and how these are framed in order to mobilise a putative dispersed population.     

Understanding selection bias,time-lags and measurement bias in secondary data sources: Putting the Encyclopedia of Associations database in broader context

Secondary data gathered for purposes other than research play an important role in the social sciences. A recent data release has made an important source of publicly available data on associational interests, the Encyclopedia of Associations (EA), readily accessible to scholars (www.policyagendas.org). In this paper we introduce these new data and systematically investigate issues of lag between events and subsequent reporting in the EA, as these have important but under-appreciated effects on time-series statistical models. We further analyze the accuracy and coverage of the database in numerous ways. Our study serves as a guide to potential users of this database, but we also reflect upon a number of issues that should concern all researchers who use secondary data such as newspaper records, IRS reports and FBI Uniform Crime Reports.     

To Pool or Not to Pool in Call Centers

Should service capacities (such as agent groups in call centers) be pooled or not? This paper will show that there is no single answer. For the simple but generic situation of two (strictly pooled or unpooled) server groups, it will provide (1) insights and approximate formulae, (2) numerical support, and (3) general conclusions for the waiting‐time effect of pooling. For a single call type, this effect is clearly positive, as represented by a pooling factor. With multiple job types, however, the effect is determined by both a pooling and a mix factor. Due to the mix factor, this effect might even be negative. In this case, it is also numerically illustrated that an improvement of both the unpooled and the strictly pooled scenario can be achieved by simple overflow or threshold scenarios. The results are of both practical and theoretical interest: practical for awareness of this negative effect, the numerical orders, and practical scenarios in call centers, and theoretical for further research in more complex situations.     

The Trace Restriction: An Alternative Identification Strategy for the Bayesian Multinomial Probit Model

Previous authors have made Bayesian multinomial probit models identifiable by fixing a parameter on the main diagonal of the covariance matrix. The choice of which element one fixes can influence posterior predictions. Thus, we propose restricting the trace of the covariance matrix, which we achieve without computational penalty. This permits a prior that is symmetric to permutations of the nonbase outcome categories. We find in real and simulated consumer choice datasets that the trace-restricted model is less prone to making extreme predictions. Further, the trace restriction can provide stronger identification, yielding marginal posterior distributions that are more easily interpreted.