Drawing on data from a survey of 430 families who were recipients of a government financial assistance scheme, the study found that different types of children issues affected different types of psychological self-concepts experienced by the sample of low-income parents. While parents' sense of self-efficacy was decreased by children's poor grades, parenting stress was aggravated by both children's health and behaviour problems. The effects were stronger for parents with teenage children than parents with younger children. The findings imply the importance of better integration of services to meet the different needs of low-income families, and of a supportive manner of providing assistance. 相似文献
We examined gender-based household welfare differences in Ghana among smallholder households. We measured disparities in welfare outcomes (food poverty, vulnerability, and food consumption inequality) across male and female household heads and identified the set of covariates influencing them. The study utilizes a dataset from a farm household survey undertaken in Northern Ghana from October to December 2018. A multistage sampling approach was adopted in selecting 900 farm households. The Oaxaca–Blinder mean and Recentered Inference Function decomposition techniques highlighted the sources of gender differentials in household welfare outcomes. The findings indicate a significant gap in food consumption expenditure per capita and household dietary diversity scores between male- and female- headed households, and these gaps are as high as 28.2% and 18.1%, respectively. However, there are no statistically significant differences in vulnerability to food poverty between male- and female-headed households. The Lorenz curves confirm inequality in gendered households’ food consumption expenditure and dietary diversity scores. This study highlights the existence of systemic female-headed household vulnerability to food poverty in Ghana. This study provides significant evidence of the need for policymakers to address food systems’ structural deficiencies and inequalities with gender in mind.
ABSTRACT In this article, we create a decomposition that represents and describes the depen-dence structure between two variables. Since copulas provide a deep understanding of the dependence structure by eliminating the effects of the marginals, they play a key role in this study. We define a discretized copula density matrix and decompose it into a set of permutation matrices by using the Birkhoff–von Neumann theorem. This decomposition provides a way to effectively apply the concepts of copulas to solve problems in multivariate statistical data analysis. 相似文献
One of the most basic topics in many introductory statistical methods texts is inference for a population mean, μ. The primary tool for confidence intervals and tests is the Student t sampling distribution. Although the derivation requires independent identically distributed normal random variables with constant variance, σ2, most authors reassure the readers about some robustness to the normality and constant variance assumptions. Some point out that if one is concerned about assumptions, one may statistically test these prior to reliance on the Student t. Most software packages provide optional test results for both (a) the Gaussian assumption and (b) homogeneity of variance. Many textbooks advise only informal graphical assessments, such as certain scatterplots for independence, others for constant variance, and normal quantile–quantile plots for the adequacy of the Gaussian model. We concur with this recommendation. As convincing evidence against formal tests of (a), such as the Shapiro–Wilk, we offer a simulation study of the tails of the resulting conditional sampling distributions of the Studentized mean. We analyze the results of systematically screening all samples from normal, uniform, exponential, and Cauchy populations. This pretest does not correct the erroneous significance levels and makes matters worse for the exponential. In practice, we conclude that graphical diagnostics are better than a formal pretest. Furthermore, rank or permutation methods are recommended for exact validity in the symmetric case. 相似文献
Checking compatibility for two given conditional distributions and identifying the corresponding unique compatible marginal distributions are important problems in mathematical statistics, especially in Bayesian inferences. In this article, we develop a unified method to check the compatibility and uniqueness for two finite discrete conditional distributions. By formulating the compatibility problem into a system of linear equations subject to constraints, it can be reduced to a quadratic optimization problem with box constraints. We also extend the proposed method from two-dimensional cases to higher-dimensional cases. Finally, we show that our method can be easily applied to checking compatibility and uniqueness for a regression function and a conditional distribution. Several numerical examples are used to illustrate the proposed method. Some comparisons with existing methods are also presented. 相似文献
Baysian inference is considered for the precision matrix of the multivariate regression model with distribution of the random responses belonging to the multivariate scale mixtures of normal distributions. The posterior distribution and some identities involving expectations taken with respect to this posterior distribution are derived when the prior distribution of the parameters is from the conjugate family. The results are specialized to the case where the random responses have a matrix-t distribution and thus generalizing the results of Zellner (1976
Zellner , A. ( 1976 ). Bayesian and non-Bayesian analysis of the regression model with multivariate Student-t error terms . J. Amer. Statist. Assoc. 71 : 400 – 405 .[Taylor & Francis Online], [Web of Science ®], [Google Scholar]) and Muirhead (1986
Muirhead , R. J. ( 1986 ). A note on some Wishart expectations . Metrika 33 : 247 – 251 .[Crossref], [Google Scholar]). 相似文献
This paper analyses a linear model in which both the mean and the precision change exactly once at an unknown point in time. Posterior distributions are found for the unknown time point at which the changes occurred and for the ratio of the precisions. The Bayesian predictive distribution of k future observations is also derived. It is shown that the unconditional posterior distribution of the ratio of precisions is a mixture of F-type distributions and the predictive distribution is a mixture of multivariate t distributions. 相似文献
The joint-risk estimate of the survival function, used for censored survival data grouped into fixed intervals, is shown to be the geometric mean of all the product-limit estimates that correspond to all the possible orderings of all the failure times and censoring times in the group. The joint-risk estimate is proposed as a more appropriate and better means of dealing with ties for data containing tied failure times and censoring times. It is also applicable to competing risk problems with tied failure times involving different causes. It could be used as a substitute for the product-limit estimate in discrete failure time analysis. 相似文献