Some tests for the power series distibutions in one parameter using the kullback-leibler information measure

The purpose of the article is, in case of one sample, to obtain tests concerning the parameter in the power series distribution in one parameter using Ku11back-Leibier information measure. The class of power series distibutions contains a host of discrete distributions. Ve illustrate the general results obtained in case of the geometric distibution.     

How Australian Female Muslim Students Interpret Challenges in High School Sports

Abstract

The present study focuses on the experiences of female Muslim students in school sporting activities in Australian public high schools. Specifically, the study examines how the students interpret their engagement in relation to their Islamic background. The study aims to provide deeper understanding and greater awareness of female Muslim students’ participation in sporting activities within the public high school environment and the challenges they may face. The study employed critical race and social identity theories as an analytical framework. In addition, the study utilized qualitative research methods. Semi-structured interviews were conducted with 11 female Muslim students and 4 teachers responsible for sporting activities in school. The findings of the study reveal that despite a variety of sporting activities provided by Australian public high schools, some of these activities were challenging for Muslim girls to participate in. The study also found that there is a strong relationship between students’ Islamic background and their participation in schools sporting activities. The study recommends that educators and teachers who work with youth from different background are provided training on equity issues arising from ethnicity, race, culture, religion and other identity categories.     

A new aging concept derived from the increasing convex ordering

In this paper, a comparison between the life distribution of a new unit with that of a used unit in the increasing convex order is made leading to a new class of life distributions which we call “new better than used in convex ordering of second order”. This class includes as subclasses the NBU and the NBUC and is a subclass of the NBUCA class. Preservation properties under convolution, random maxima, mixing and formation of coherent structures are established. Stochastic comparisons of the excess lifetime when the inter-arrival times belong to the NBUC(2) class are developed. Some applications of Poisson shock models and a test of exponentiality against NBUC(2) alternative are presented.     

Sugar,Slavery and Productivity in Jamaica, 1750–1807

The article revisits one of the most significant questions in the historiography of British West Indian slavery and abolition. It examines the argument that the relatively weak state of the British West Indian economy from the 1780s onward was the main reason why Britain abolished the slave trade in 1807. In confronting this question of decline, the article analyzes the largest and most important slave plantation economy – Jamaica – during the early eighteenth and nineteenth centuries. Using newly generated indicators such as total factor productivity and national income, the paper constructs a case for the dynamism and efficiency of the plantation system in Jamaica right up to abolition in 1807.     

Environmental practices and firm performance in emerging markets: the mediating role of product quality

Environmental practices have not received as much research attention in emerging market contexts as traditional topics like quality. However, the importance of environmental practices for a firm’s production strategy has been increasing at an unprecedented level across the globe. Our research objective is, therefore, to investigate the interplay between environmental practices and quality in the pursuit of firm performance. Relying on 492 responses from Turkish manufacturers to test our hypotheses, we show that environmental practices directly improve the quality of products over and above the effect of quality management practices in emerging markets. Product quality, in turn, is important for increasing firm performance, acting as a mediator for the positive effects of environmental practices on performance. Thus, we reveal that product quality functions as an instrumental conduit between environmental practices and firm performance in emerging markets like Turkey where stakeholder pressures are weak, and regulations are often not properly enforced.     

Tweeting India’s Nirbhaya protest: a study of emotional dynamics in an online social movement

Abstract

Previous research has recognized the role of emotions in protests and social movements in the offline world. Despite the current scenario of ubiquitous social media and ‘Twitter revolutions,’ our knowledge about the connections between emotions and online protests still remains limited. In this study, we examine whether online protest actions follow the same emotional groundwork for supporting and nurturing a social movement as in the offline world, and how these emotions vary across various stages of the social movement. Through a computer-assisted emotion analysis of 65,613 Twitter posts (tweets), posted during the Nirbhaya social movement (movement against the Delhi gang-rape incident) in India, we identified a strong resemblance between online emotional patterns and offline protest emotions as discussed in literature. Formal statistical testing of a range of emotions (negativity, positivity, anger, sadness, anxiety, certainty, individualism, collectivism, and achievement) demonstrates that they significantly differed across stages of the social movement; as such, they influenced the course of the online protest, resonating parallels with offline events. The findings highlight the importance of anger and anxiety in stirring the collective conscience, and identify that positive emotion was pervasive during the protest event. Implications of these findings are discussed.     

Merging data from multiple sources: pretest and shrinkage perspectives

In this article, we have developed asymptotic theory for the simultaneous estimation of the k means of arbitrary populations under the common mean hypothesis and further assuming that corresponding population variances are unknown and unequal. The unrestricted estimator, the Graybill-Deal-type restricted estimator, the preliminary test, and the Stein-type shrinkage estimators are suggested. A large sample test statistic is also proposed as a pretest for testing the common mean hypothesis. Under the sequence of local alternatives and squared error loss, we have compared the asymptotic properties of the estimators by means of asymptotic distributional quadratic bias and risk. Comprehensive Monte-Carlo simulation experiments were conducted to study the relative risk performance of the estimators with reference to the unrestricted estimator in finite samples. Two real-data examples are also furnished to illustrate the application of the suggested estimation strategies.     

Effects of some design factors on the distribution of similarity indices in cluster analysis

This article investigates the effects of number of clusters, cluster size, and correction for chance agreement on the distribution of two similarity indices, namely, Jaccard and Rand indices. Skewness and kurtosis are calculated for the two indices and their corrected forms then compared with those of the normal distribution. Three clustering algorithms are implemented: complete linkage, Ward, and K-means. Data were randomly generated from bivariate normal distributions with specified means and variance covariance matrices. Three-way ANOVA is performed to assess the significance of the design factors using skewness and kurtosis of the indices as responses. Test statistics for testing skewness and kurtosis and observed power are calculated. Simulation results showed that independent of the clustering algorithms or the similarity indices used, the interaction effect cluster size x number of clusters and the main effects of cluster size and number of clusters were found always significant for skewness and kurtosis. The three way interaction of cluster size x correction x number of clusters was significant for skewness of Rand and Jaccard indices using all clustering algorithms, but was not significant using Ward's method for both Rand and Jaccard indices, while significant for Jaccard only using complete linkage and K-means algorithms. The correction for chance agreement was significant for skewness and kurtosis using Rand and Jaccard indices when complete linkage method is used. Hence, such design factors must be taken into consideration when studying distribution of such indices.     

Detecting structural change with heteroskedasticity

The hypothesis of structural stability that the regression coefficients do not change over time is central to all applications of linear regression models. It is rather surprising that existing theory as well as practice focus on testing for structural change under homoskedasticity – that is, regression coefficients may change, but the variances remain the same. Since structural change can, and often does, involve changes in variances, this is a puzzling gap in the literature. Our main focus in this paper is to utilize a newly developed test (MZ) by Maasoumi et al. (2010 Maasoumi, E., Zaman, A., Ahmed, M. (2010). Tests for structural change, aggregation, and homogeneity. Econ Model. 27(6):1382–1391.[Crossref], [Web of Science ®] , [Google Scholar]) that tests simultaneously for break in regression coefficients as well as in variance. Currently, the sup F test is most widely used for structural change. This has certain optimality properties shown by Andrews (1993 Andrews, D.W.K. (1993). Test for parameter instability and structural change with unknown change point. Econometrica. 61(4):821–856.[Crossref], [Web of Science ®] , [Google Scholar]). However, this test assumes homoskedasticity across the structural change. We introduce the sup MZ test which caters to unknown breakpoints, and also compare it to the sup F. Our Monte Carlo results show that sup MZ test incurs only a low cost in case of homoskedasticity while having hugely better performance in case of heteroskedasticity. The simulation results are further supported by providing a real-world application. In real-world datasets, we find that structural change often involves heteroskedasticity. In such cases, the sup F test can fail to detect structural breaks and give misleading results, while the sup MZ test works well. We conclude that the sup MZ test is superior to current methodology for detecting structural change.