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871.
In this note we consider the equality of the ordinary least squares estimator (OLSE) and the best linear unbiased estimator
(BLUE) of the estimable parametric function in the general Gauss–Markov model. Especially we consider the structures of the
covariance matrix V for which the OLSE equals the BLUE. Our results are based on the properties of a particular reparametrized version of the
original Gauss–Markov model.
相似文献
872.
Randomized response techniques are widely employed in surveys dealing with sensitive questions to ensure interviewee anonymity
and reduce nonrespondents rates and biased responses. Since Warner’s (J Am Stat Assoc 60:63–69, 1965) pioneering work, many
ingenious devices have been suggested to increase respondent’s privacy protection and to better estimate the proportion of
people, π
A
, bearing a sensitive attribute. In spite of the massive use of auxiliary information in the estimation of non-sensitive parameters,
very few attempts have been made to improve randomization strategy performance when auxiliary variables are available. Moving
from Zaizai’s (Model Assist Stat Appl 1:125–130, 2006) recent work, in this paper we provide a class of estimators for π
A
, for a generic randomization scheme, when the mean of a supplementary non-sensitive variable is known. The minimum attainable
variance bound of the class is obtained and the best estimator is also identified. We prove that the best estimator acts as
a regression-type estimator which is at least as efficient as the corresponding estimator evaluated without allowing for the
auxiliary variable. The general results are then applied to Warner and Simmons’ model. 相似文献
873.
Estimation of a relative potency of two preparations in so-called parallel-line assays is presented. A special type of incomplete
Latin square designs where doses of preparations are administered is considered. Testing hypotheses about similarity of preparations
and their relative potency in the case of correlated observations are regarded. Confidence interval for the relative potency
of preparations is also given. Theoretical considerations are applied to point and interval estimation of potencies of new
tuberculins with respect to some international standards tested in experiments on guinea-pigs. 相似文献
874.
D. James Greiner Kevin M. Quinn 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2009,172(1):67-81
Summary. Despite its potential pitfalls, ecological inference is an unavoidable part of some quantitative settings, including US voting rights litigation. In such applications, the analyst will typically encounter two-way tables with more than two rows and columns. Although several ecological inference methods are currently available for 2×2 tables, there are fewer options for analysing general R × C tables, and virtually none that model counts as opposed to fractions. We propose a count R × C method that respects the bounds deterministically, that allows for complex relationships between internal cell quantities, that is easily extensible and that results from transparent assumptions. We study the method via simulation, and then apply it to an example that is drawn from the state of Texas relevant to recent redistricting litigation there. 相似文献
875.
Pauline W. Jansen Cathelijne L. Mieloo Anke Dommisse-van Berkel Marina Verlinden Jan van der Ende Gonneke Stevens Frank C. Verhulst Wilma Jansen Henning Tiemeier 《Race and social problems》2016,8(4):271-280
School-aged children with an ethnic minority background are relatively often involved in bullying and victimization, but the role of ethnic composition of schools in this context remains unclear. This study examined the relation between ethnic minority background, ethnic school composition, and bullying behaviour around primary school entry in the Netherlands. The study was based on a 2008/2009 school survey in Rotterdam, a Dutch city where about 50 % of children have a non-Dutch background. For 8523 children, teacher reports of bullying behaviour at age 5–6 years were available. Children with a non-Dutch background had higher odds of being a victim (adjusted OR 1.41, 95 % CI 1.11, 1.80), bully (OR 1.38, 95 % CI 1.20, 1.58) or bully-victim (OR 1.38, 95 % CI 1.19, 1.62) than children of Dutch national origin. Ethnic diversity in schools increased children’s risk of bullying behaviour (e.g. ORvictim per 0.1 increase in 0–1 diversity range = 1.06, 95 % CI 1.00, 1.13), with children of both Dutch and non-Dutch national origin relatively more often involved in bullying in ethnically diverse schools. The proportion of same-ethnic peers in school reduced the risk of bullying among children of Dutch national origin (e.g. ORvictim per 10 % more same-ethnic children = 0.90, 95 % CI 0.83, 0.98), but not among non-Dutch children. In conclusion, ethnic minority background and ethnic diversity within schools are risk factors for bullying among 5–6 year olds. Plausibly, reductions in absolute numbers of bullying events may be obtained with tailor-made interventions in ethnically diverse schools. Such interventions should preferably be offered early in the school curriculum. 相似文献
876.
Using data from the 2013 Survey of Consumer Finances, this research examines competing and complementary cultural and structural explanations of the sources of racial differences in wealth. We use OLS regression and quantile regression to identify the major individual-level sources of wealth differences between African Americans and whites. Whites have more favorable wealth characteristics than do African Americans on all of the variables in the analysis: gender of household head, bankruptcies, spending patterns, stock ownership, business ownership, home ownership, inheritance, educational attainment, income, occupation, age, and number of children. Cultural factors, having a female-headed family, spending patterns, and inheritance account for little of the racial wealth gap. Racial differences in income, stock ownership, and business ownership account for much of the explained racial wealth gap. Moreover, compared with whites, African Americans receive significantly lower wealth returns to education, age, income, stock ownership, and business ownership. We discuss the implications of our findings. 相似文献
877.
Although racial profiling is widely studied, the related issue of citizenship profiling by law enforcement has received little scholarly attention. In this study we begin to address citizenship profiling, which may be highly salient in light of the increasing policing of immigration in the United States through Secure Communities and other federal, state and local efforts to localize the enforcement of immigration laws. Using a sample of 563 Latina/o adults residing in 46 neighborhoods in El Paso County, Texas, USA, we assess the impacts of a variety of individual and neighborhood characteristics on the likelihood of being questioned about citizenship status by law enforcement. Results using hierarchical generalized linear models (HGLMs) show that, at the individual-level, first-generation Latina/o immigrants and second-Latina/os are more likely to be questioned about citizenship status than third- and later-generation Latina/os. At the neighborhood-level, living in a neighborhood with a mid-level of Latina/o immigrant characteristics increased the probability of being questioned. The implications of these findings for citizenship profiling are discussed. 相似文献
878.
San Juanita García 《Race and social problems》2018,10(3):221-234
Previous sociological research shows that exposure to stress varies by individuals’ social statuses and is a central mechanism in producing mental health disparities. This line of research suggests that ethnoracial groups are more exposed to racial discrimination, thus negatively impacting their mental health. There has also been a growing literature showing how legal status impacts the mental health of immigrants and their families. However, the sociology of mental health and migration literature has largely remained disparate. This paper bridges these literatures to highlight how living a deportation threat manifests itself as an anticipatory stressor that negatively impacts undocumented Mexican migrant women’s access to resources, social relationships, and social roles. Based on 30 semi-structured in-depth interviews with undocumented Mexican immigrant women from Houston, Texas, my findings reveal living a deportation threat is a perpetual anticipatory stressor that intensifies the effects of avoiding authorities, family fragmentation, and economic uncertainty. I argue this anticipatory stressor transforms into a chronic stressor that undocumented Mexican women confront daily. By situating this study within an anti-immigrant social context, it highlights the social processes and mechanisms that exacerbate the stressors undocumented Mexican immigrant women confront. 相似文献
879.
Research has established that being undocumented is a risk factor for mental and physical health conditions. Much of this work emphasizes undocumented immigrants’ chronic stress, yet key questions about pathways to health remain. The mere state of being undocumented is viewed as a general stressor, without considering actual levels of stress or identifying dimensions of documentation status that contribute to overall stress levels. Drawing on surveys and interviews with undocumented students at the University of California, we uncover the everyday manifestations of four dimensions of immigrant “illegality”: academic concerns, future concerns, financial concerns, and deportation concerns, and their association with reported stress levels and self-rated health. Survey data establish undocumented students’ high levels of stress and poorer health, in comparison to previous research on other national samples. In a structural equation model, we found academic and future concerns to be significantly associated with higher stress, which was in turn, associated with poorer self-rated health. Financial concerns were not associated with higher perceived stress but were directly associated with poorer self-rated health. Notably, deportation concerns did not have any significant independent associations with stress or health. We use our qualitative data to identify specific stressors embedded within these four dimensions. Our findings inform understandings of the health risks arising from documentation status. 相似文献
880.
风险社会背景下大学生的信仰危机 总被引:2,自引:0,他引:2
当今,世界正由工业社会向风险社会过渡,信仰危机是当代人类面临的全球性问题,信仰危机的出现要求我们关注信仰教育。受全球化的影响,中国也处于风险社会之中。大学生作为我国社会主义事业的接班人,其信仰状况直接关系到国家的前途和命运。本文首先阐述了信仰以及信仰危机的含义,然后分析了我国大学生当前存在的信仰危机及其产生的原因,最后对于解决我国大学生的信仰危机提出了几点建议。 相似文献