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41.
We present a decomposition of the correlation coefficient between xt and xt?k into three terms that include the partial and inverse autocorrelations. The first term accounts for the portion of the autocorrelation that is explained by the inner variables {xt?1 , xt?2 , …, x t? k+1}, the second one measures the portion explained by the outer variables {x t+1, x t+2, } ∪ {x t?k?1, x t?k?2,…} and the third term measures the correlation between x t and xt?k given all other variables. These terms, squared and summed, can form the basis of three portmanteau-type tests that are able to detect both deviation from white noise and lack of fit of an entertained model. Quantiles of their asymptotic sample distributions are complicated to derive at an adequate level of accuracy, so they are approximated using the Monte Carlo method. A simulation experiment is carried out to investigate significance levels and power of each test, and compare them to the portmanteau test.  相似文献   
42.
This paper aims to contribute to the empirical evidence relating corporate social responsibility (CSR), board composition, and firm performance. Using a sample of Spanish listed firms included in the IBEX 35 over the period 2005–2010 the results show that the percentage of independent directors affect firm CSR activities, and that this effect is moderated by the resources available to the firm (measured by return on assets). Also, the CSR has a mediating role on the relation between the independence of the board of directors and firm value. These results hold for other board characteristics (board size and women as directors).  相似文献   
43.
Usually in latent class (LC) analysis, external predictors are taken to be cluster conditional probability predictors (LC models with external predictors), and/or score conditional probability predictors (LC regression models). In such cases, their distribution is not of interest. Class-specific distribution is of interest in the distal outcome model, when the distribution of the external variables is assumed to depend on LC membership. In this paper, we consider a more general formulation, that embeds both the LC regression and the distal outcome models, as is typically done in cluster-weighted modelling. This allows us to investigate (1) whether the distribution of the external variables differs across classes, (2) whether there are significant direct effects of the external variables on the indicators, by modelling jointly the relationship between the external and the latent variables. We show the advantages of the proposed modelling approach through a set of artificial examples, an extensive simulation study and an empirical application about psychological contracts among employees and employers in Belgium and the Netherlands.  相似文献   
44.
Parenting models are generally based on families in stable homes, rather than in transitional situations such as in foster care, homeless shelters, and other temporary, at-risk residences. Consequently, these models do not recognize the unique challenges of families in transition. This study explored the domains of the Circumplex Model and examined its fit for transitional families using tenets from community-based participatory research. Findings suggest that in addition to the Circumplex Model's components, caregivers with children living in transition believe that managing the scrutiny of external authority systems and countering the negative influences of poverty and racism are two indicators that contribute to parenting success. Obtaining consumer-informed views of parenting not only is an important contributor to standards of practice, but also a promising avenue for future research.  相似文献   
45.
The objectives of the present study were to analyze the pattern of tobacco use among Spanish adolescents, as well as to determine gender differences in specific risk factors of cigarette use. The study sample was made up of 1,483 boys and 1,358 girls, aged 12-16 (M = 14). Participants were asked to answer an ad-hoc instrument to evaluate the pattern of use, perceived availability, risk of harm, family- and peer-use, engagement in leisure activities, drive for thinness, and self-esteem. Results showed no gender differences in the pattern of use. With regard to risk and protector factors, a predictive analysis showed that peer-related variables were the most determinant for tobacco use both for boys and girls. Some gender differences were also detected: Playing sports was protective for boys only, and listening to music for girls only. Drive for thinness and self-esteem were not related to tobacco use for either boys or girls. These findings help increase our understanding of smoking risk factors in adolescence and to pay special attention to the group of friends when planning prevention programs to reduce risk factors.  相似文献   
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47.
Many white noise and goodness-of-fit tests are (asymptotically) written as quadratic forms in the ordinary autocorrelation estimates. The properties of such tests are studied by investigating the structure of the matrix of the quadratic form. We suggest to choose the matrix of the quadratic form in such a way that the power is maximized according to the information available about the alternative hypothesis. A simulation study sheds some light on the behavior of the test in finite samples. It is generally found more powerful than the most popular portmanteau tests, i.e., the Box and Pierce and the Ljung and Box tests.  相似文献   
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49.
Recent investigations about notions of bivariate aging have underlined the need to introduce some new properties of positive dependence for a bivariate random vector. Here, by using the recent notion of supermigrativity of a bivariate copula, a?positive dependence property is introduced and investigated. Comparisons with other notions of positive dependence are also presented.  相似文献   
50.
Systematic review and meta-analysis of literature were conducted examining the effectiveness of the National Institute for Child Health and Human Development Investigative Interview Protocol in improving the quality of child forensic interviews. Online databases were searched for journal articles published between the years 2000 and 2013. Measures of interview quality were the type of interviewer utterances and the amount of information provided by children. Five studies met criteria for inclusion in the meta-analysis. Weighted mean of the effect sizes was calculated for each outcome measure. Protocol interviews had more invitations (g = 1.60) and fewer option-posing (g = ?.95) and suggestive prompts (g = ?.63) than standard interviews. Children interviewed by the protocol provided more central details (g = .90) in response to invitations than controls. Meta-analyses of a subset of preschool children samples revealed that protocol interviews had more invitations (g = 1.46), fewer suggestive prompts (g = ?.61), and fewer option-posing prompts (g = ?1.05) than controls. Findings corroborate results from previous studies that suggested the benefits of the protocol on the interviewers’ performance and on children’s informativeness. However, protocol did not show the same performance with regard to preschool children.  相似文献   
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