Testing for Persistence in the Error Component Model: A One-Sided Approach

This article proposes new simple testing procedures for the joint null hypothesis of absence of persistent effects, in the form of random effects and first-order serial correlation in the error component model. The fact that the presence of random effects is clearly of a one-sided nature, together with the fact that in many empirical applications researchers worry about positive serial correlation leaves room for a power gain that arises from restricting the parameter space under the alternative hypothesis, compared to existing procedures that allow for two-sided alternatives. A Monte Carlo experiment shows that the proposed statistics have good size and power performance in very small samples like those typically used in applied work in panel data. An empirical example illustrates the usefulness of the proposed statistics.     

Data-Driven Tests for Trend

This article proposes a new nonparametric test for the ordered alternatives problem in the k-sample setting for null hypothesis of lack of trend. This article further elaborates upon and extends the results of Ledwina and Wy?upek (2012a Ledwina , T. , Wy?upek , G. ( 2012a ). Two-sample test against one-sided alternatives . Scand. J. Statist. 39 : 358 – 381 .[Crossref], [Web of Science ®] , [Google Scholar]) obtained for k = 2. Simulations show that the new test has high and stable power and is able to control the Type I error to satisfactory extent, thus solving the problem posed in Terpstra and Magel (2003 Terpstra , J. T. , Magel , R. C. ( 2003 ). A new nonparametric test for the ordered alternative problem . J. Nonparametr. Statist. 15 : 289 – 301 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). Our theoretical results say that asymptotic errors of both kinds do not exceed significance level, thus implying that the test is asymptotically unbiased.     

Locally Most Powerful Rank Tests for Comparison of Two Failure Rates Based on Multiple Type-II Censored Data

This article deals with the locally most powerful rank tests for testing the hypothesis that two failure rates are equal against the alternative that one failure rate is greater than the other, when the combined ordered sample is multiple Type-II censored. A modified version of the Dupa? and Hájek (1969 Dupa? , V. , Hájek , J. (1969). Asymptotic normality of simple linear rank statistics under alternatives II. Ann. Math. Statist. 40:1992–2017.[Crossref] , [Google Scholar]) theorem is used to establish their asymptotic normality under fixed alternative since the scores generating functions associated with these rank test statistics have a finite number of jump discontinuities. The modified version that leads to a simpler centering constant, is proved by Dupa? (1970 Dupa? , V. ( 1970 ). A contribution to the asymptotic normality of simple linear rank statistics. In: Puri, M. L., ed. Nonparametric Techniques in Statistical Inference. Cambridge: Cambridge University Press . [Google Scholar]) using the results of Hájek (1968 Hájek , J. ( 1968 ). Asymptotic normality of simple linear rank statistics under alternatives . Ann. Math. Statist. 39 : 325 – 346 .[Crossref] , [Google Scholar]). The Pitman AREs of these rank tests based on censored data relative to the corresponding tests based on complete data are obtained under some Lehmann-type alternative distributions such that their failure rates dominate the failure rates of the respective null distributions. The AREs are computed numerically for single (left or right) and double censored data, and the extent of loss due to these censoring schemes is discussed. The rank tests considered here include among them the Mann-Whiney-Wilcoxon (MWW) test, the Savage test, and the linear combination of these two tests. In the case of all the tests, except the MWW test, it is found that the loss of efficiency due to left censoring is considerably less than that due to right censoring. In the case of finite samples, Monte Carlo simulation results showing the empirical levels and empirical powers against some Lehmann alternatives are presented.     

A modified Mack–Wolfe test for the umbrella alternative problem

ABSTRACT

The Mack–Wolfe test is the most frequently used non parametric procedure for the umbrella alternative problem. In this paper, modifications of the Mack–Wolfe test are proposed for both known peak and unknown peak umbrellas. The exact mean and variance of the proposed tests in the null hypothesis are also derived. We compare these tests with some of the existing tests in terms of the type I error rate and power. In addition, a real data example is presented.     

Stabilizing the Performance of Kurtosis Estimator of Multivariate Data

The estimation of the kurtosis parameter of the underlying distribution plays a central role in many statistical applications. The central theme of the article is to improve the estimation of the kurtosis parameter using a priori information. More specifically, we consider the problem of estimating kurtosis parameter of a multivariate population when some prior information regarding the the parameter is available. The rationale is that the sample estimator of the kurtosis parameter has a large estimation error. In this situation we consider shrinkage and pretest estimation methodologies and reappraise their statistical properties. The estimation based on these strategies yield relatively smaller estimation error in comparison with the sample estimator in the candidate subspace. A large sample theory of the suggested estimators are developed and compared. The results demonstrate that suggested estimators outperform the estimator based on the sample data only in the candidate subspace. In an effort to appreciate the relative behavior of the estimators in a finite sample scenario, a Monte-carlo simulation study is planned and performed. The result of simulation study strongly corroborates the asymptotic result. To illustrate the application of the estimators, some example are showcased based on recently published data.     

“I did not know there was another life”: Meanings of life in the out‐of‐home Mothers Unit reunification programme

The Mothers Unit is a reunification and treatment programme in a welfare emergency centre in Israel. The unit is the only one in Israel offering joint residence for mothers at risk of abusing or neglecting their children. The unit provides an alternative to out‐of‐home care for young children suffering from maltreatment in order to enable them and their mothers to return to the community together at the end of the treatment. The current qualitative study examines the lived experiences of the women and their children from the subjective perspective of the women currently or previously involved in the programme and of the professionals working with them. Thematic analysis of 36 in‐person semi‐structured interviews reveals the multiple meanings they attribute to life in the Mothers Unit and its perceived effects on their children and themselves.     

自由与责任:一种政治哲学的分析

自由和责任是一对孪生概念。但分别从自由出发和从责任出发来处理责任-自由的关系, 我们看到的是两种根本不同的观点。这两种观点体现了两种不同的主体性,即权利在先意识和责任在先意识。分析这两种主体性在社会生活和政治生活中的运行,可以帮助我们从根本上理解当代中西方政治生活的差异性。在权利意义上的自由指的是人在选择中至少面临一种“想要选项”;而责任概念的关键点是个体面向未来、他人和它者。权利在先意识引导着自由主体性,在政治生活上主张把某种普遍的“想要选项”作为人的基本权利,这种政治称为权利政治。责任在先意识所引导的责任主体性,则把政治生活奠基于主体对未来、他人和任务的深入理解,要求每一个人不断培养自己的责任感,并对政治家的责任感提出更高要求,这便是问责政治。这两种由不同主体性所承担的政治体制各有利弊,简单地互相否定不会给我们人类带来任何好处。     

Pooling reliability functions

In this article large sample pooling procedures for reliability functions of an exponential life testing model is considered. Asymptotic properties of shrinkage estimation procedure subsequent to preliminary tests are developed. It is shown that the proposed estimator possesses substantially snakker asymptotic mean squared error than the usual estimator in a region of the lparameter space. Relative efficiencies of the purposed estimators to the usual estimators are obtained and recommendations of the level of the preliminary tests are provided. Relative dominance picture of the estimators is presented. It is shown that the proposed estimator provides a wider dominance range over usual estimator than the usual preliminary test estimator. More importantly, the size of the preliminary test is meaningful. Simulation studies is also carried out to appraise the performance of the estimators when samples are small.     

Demographic Comparisons of Aging in Five Selected Countries

The worldwide aging of the population is having a major impact upon society. The United Nations General Assembly has declared 1999 to be the International Year of Older Persons to increase the awareness of aging worldwide. They identified five principles for older persons: independence, participation, care, self-fulfillment, and dignity. The numbers of elderly are growing around the world with many elderly living considerably longer than in past times. Developed countries are struggling with the high cost of maintaining support programs, and developing countries face dissolution of traditional care systems without institutional replacements. Women around the globe typically live longer than men, often without the economic resources to maintain independence. As nations adapt to their aging populations, a partnership among policy makers, family members, and older persons themselves is needed to offer alternatives to meet the needs of elders.