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A method is proposed in this paper to assess the local influence of minor perturbations for the Sharpe model when the normal distribution is replaced by normal/independent (NI) distributions. The family of NI distributions is an attractive class of symmetric heavy-tailed densities that includes as special cases the normal, t-Student, slash, and the contaminated normal distributions. Since the returns of the market are not observable, the statistical analysis is carried out in the context of an errors-in-variables model. An influence analysis for detecting influential observations (atypical returns) is developed to investigate the sensitivity of the maximum likelihood estimators. Diagnostic measures are obtained based on the conditional expectation of the complete-data log-likelihood function. The results are illustrated by using a set of shares of companies traded in the Chilean stock market. 相似文献
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Social Indicators Research - The article The Impact of Agricultural Technologies on Poverty and Vulnerability of Smallholders in Ethiopia: A Panel Data Analysis, written by Wubneshe Dessalegn Biru,... 相似文献
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This paper addresses the questions of market penetration and locational conflict in a franchise system of distribution. The models developed provide a means to evaluate alternative scenarios and the effects of various franchise policies. It is shown that the market penetration and location goals of the members of a franchise system coincide only under a very limited set of circumstances. 相似文献
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Adinda Dujardin Rudi De Raedt Jessica L. Borelli Caroline Braet Pieter Vos Mike Rinck Guy Bosmans 《Social Development》2019,28(2):364-382
In this study we investigated the effects of seeking versus avoiding proximity to mother on children’s emotional recovery from a stressor. Sixty children 9–12 years underwent a moodinduction procedure and were randomly assigned to seek proximity from or avoid an image of their mothers. The effect of this manipulation on children’s self‐reported negative emotions, skin conductance and heart rate variability (respiratory sinus arhythmia) was assessed. Higher levels of attachment anxiety were linked to more self‐reported sadness when children had to avoid mother, but no evidence for such an effect was found on a physiological level. For avoidant attachment, a similar pattern of results emerged, but both for self‐reported sadness and skin conductance. 相似文献
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Zaine Isabela Domeniconi Camila de Rose Julio C. 《The Analysis of verbal behavior》2014,30(2):193-204
The Analysis of Verbal Behavior - This study evaluated an intervention package combining simple and conditional discrimination training and specific reinforcement for each stimulus class in... 相似文献
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The effect on mortality of socially significant events is examined using birth date as the criterion date for a large sample from official state mortality records for Ohio. The sample consisted of all deaths from natural causes for 1979-1981. "The findings show that there is a greater tendency for persons to die within thirty days after the date of birth than before. More specifically, there was a statistically significant pattern of increased mortality for those who were never married and for ill-defined causes of death. A theoretical foundation and a brief interpretation of these findings is offered." 相似文献
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The main objective of this paper is to discuss maximum likelihood inference for the comparative structural calibration model
(Barnett, in Biometrics 25:129–142, 1969), which is frequently used in the problem of assessing the relative calibrations
and relative accuracies of a set of p instruments, each designed to measure the same characteristic on a common group of n experimental units. We consider asymptotic tests to answer the outlined questions. The methodology is applied to a real data
set and a small simulation study is presented. 相似文献
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This study analysed the impact of changing family structure on income distribution. Specifically, it analysed how changes in the proportions of different categories of family in the population contributed to increases in the income of the richest and poorest social strata in Brazil, and the consequent impacts on income inequality. Rural and urban families were compared in order to understand how these dynamics had different impacts on more developed (urban) and less developed (rural) areas. The results emphasize how changes observed in family structure are more pronounced among the richest families, contributing to an increase in (i) the income of the richest families and (ii) income inequality between the richest and poorest families, as well as between urban and rural areas. 相似文献