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31.
Public opinion surveys purport to express the public's opinion. The literature on survey techniques has, however, recognized various potential limitations to the validity of survey results. While improved survey methodology may reduce statistical bias and improve validity, it cannot avoid the implicit weighting of preferences. This normative aspect of surveying has often been unrecognized or disguised as a purely technical matter. Such things as sample selection, choice of survey instrument and the method of aggregating results will each contribute to a pattern of preference weights. Several common survey techniques are examined in this light. It is proposed that no single ‘correct’ method of preference aggragation exists. Increased public recognition of, and debate on this normative aspect of surveying is recommended.  相似文献   
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Michael ST  Crowther MR  Schmid B  Allen RS 《Journal of women & aging》2003,15(2-3):145-65; discussion 185-7
Nearly half of women age 65 or older are widows and nearly 70% of these women live alone. Because older women are three times more likely than their male counterparts to be widowed, widowhood has been labeled a primarily female phenomenon. This review article has two aims: (a) to discuss the impact of widowhood on the lives of older women and (b) to discuss how religion and spirituality may be used as coping methods for conjugal loss. After reviewing the literature the authors conclude that older women use religious coping as well as religious and spiritual beliefs and behaviors to facilitate positive adjustment to the loss of a spouse.  相似文献   
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Social Indicators Research - Using tax data from the Swiss canton of Lucerne, we study how measures of economic inequality change if they account for income and wealth rather than income alone....  相似文献   
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The analysis of survival endpoints subject to right-censoring is an important research area in statistics, particularly among econometricians and biostatisticians. The two most popular semiparametric models are the proportional hazards model and the accelerated failure time (AFT) model. Rank-based estimation in the AFT model is computationally challenging due to optimization of a non-smooth loss function. Previous work has shown that rank-based estimators may be written as solutions to linear programming (LP) problems. However, the size of the LP problem is O(n 2+p) subject to n 2 linear constraints, where n denotes sample size and p denotes the dimension of parameters. As n and/or p increases, the feasibility of such solution in practice becomes questionable. Among data mining and statistical learning enthusiasts, there is interest in extending ordinary regression coefficient estimators for low-dimensions into high-dimensional data mining tools through regularization. Applying this recipe to rank-based coefficient estimators leads to formidable optimization problems which may be avoided through smooth approximations to non-smooth functions. We review smooth approximations and quasi-Newton methods for rank-based estimation in AFT models. The computational cost of our method is substantially smaller than the corresponding LP problem and can be applied to small- or large-scale problems similarly. The algorithm described here allows one to couple rank-based estimation for censored data with virtually any regularization and is exemplified through four case studies.  相似文献   
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Comparison of different estimation techniques for portfolio selection   总被引:1,自引:0,他引:1  
The main problem in applying the mean-variance portfolio selection consists of the fact that the first two moments of the asset returns are unknown. In practice the optimal portfolio weights have to be estimated. This is usually done by replacing the moments by the classical unbiased sample estimators. We provide a comparison of the exact and the asymptotic distributions of the estimated portfolio weights as well as a sensitivity analysis to shifts in the moments of the asset returns. Furthermore we consider several types of shrinkage estimators for the moments. The corresponding estimators of the portfolio weights are compared with each other and with the portfolio weights based on the sample estimators of the moments. We show how the uncertainty about the portfolio weights can be introduced into the performance measurement of trading strategies. The methodology explains the bad out-of-sample performance of the classical Markowitz procedures.  相似文献   
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Motives and values at work have long been key topics of business and management studies. In a focused review of the literature on the nature of human values, this paper identifies a disconnect with the literature on human motivation, despite the otherwise inherent relatedness of the two fields. Specifically, extant theory and research have conceptualized values generally in terms of ideals, namely desired end‐states that individuals strive to approach. Although values, by this definition, express motivational concerns, theories of human motivation suggest that there are two forces to consider, i.e. approach and avoidance motivation. By applying this ‘two forces’ perspective to value research, this paper identifies a gap in the literature on values: namely, the idea that individuals are also influenced by counter‐ideal values, i.e. end‐states that they deliberately seek to avoid. The identification of this gap opens up new opportunities for value research in general and organizational value research in particular. To pave the way for future research, this paper critically discusses the few studies that have taken first steps in that direction and outlines research questions that may follow for issues such as employer branding and person–organization fit. This paper closes by providing suggestions on how to tackle the issue in organizational practice.  相似文献   
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