Goodness-of-fit tests for Pareto distribution based on a characterization and their asymptotics

In this paper we present a new characterization of the Pareto distribution and consider goodness-of-fit tests based on it. We provide an integral and Kolmogorov–Smirnov-type statistics based on U-statistics and we calculate Bahadur efficiency for various alternatives. We find locally optimal alternatives for those tests. For small sample sizes, we compare the power of those tests with some common goodness-of-fit tests.     

Prediction of posttraumatic stress disorder symptomatology after childbirth – A Croatian longitudinal study

Background

Following childbirth, a vast number of women experience some degree of mood swings, while some experience symptoms of postpartum posttraumatic stress disorder.

Why combatants fight: the Irish Republican Army and the Bosnian Serb Army compared

This article investigates what motivates combatants to fight in non-conventional armed organizations. Drawing on interviews with ex-combatants from the Army of the Serbian Republic in Bosnia and Herzegovina and the Provisional Irish Republican Army, the article compares the role of nationalist ideology, coercive organizational structures, and small group solidarity in these two organizations. Our analysis indicates that coercion played a limited role in both armed forces: in the VRS coercion was relevant mostly in the recruitment phase, while in the IRA its direct impact was only discernible during armed operations. We also find that although both organizations are seen as being highly motivated by nationalist ideas, the picture is much more complex and nationalism is less present than expected. The study demonstrates that nationalism played a relatively marginal role in combatants’ motivation to fight. Instead our research indicates that individualist motivations, small group solidarity, and local networks dominate.     

Building Social Capability for Economic Catch-up: The Experience and Prospects of the Post-socialist Countries

The post-socialist countries are, by the standards of the EU, poor countries. The major developmental task facing these countries is, therefore, that of catching up with their more prosperous neighbours. The scope for catch-up is defined in terms of the levels of social capability exhibited by these societies and their capacity to establish technological congruence with the leading firms from the advanced industrial economies. S&T systems in the broadest sense are shown to be key factors in relation to both social capability and technological congruence. Detailed analysis of the transition countries indicates that the catch-up process is hampered across the board by specific gaps in social capability and elements of technological incongruence. These can in turn be traced to specific structural trends, in particular in relation to foreign investment, and to specific weaknesses of institutional development, cutting across the public/private dividing line, notably in relation to R&D systems and banking systems. Consideration of all these factors suggests that there can be no assumption that the transition countries will automatically catch up with western Europe, and that some disfavoured transition countries may, indeed, continue to fall behind.     

Two-dimensional Kolmogorov-type goodness-of-fit tests based on characterisations and their asymptotic efficiencies

In this paper, new two-dimensional goodness-of-fit tests are proposed. They are of supremum type and are based on two different types of characterisations. The first type are those that involve functional equations that the distribution function satisfies, while the second type uses independence of some statistics. The asymptotics of the statistics is studied and Bahadur efficiencies of the tests against some close alternatives are calculated. In the process, a theorem on large deviations of Kolmogorov-type statistics has been extended to the multidimensional case.     

Comparison of efficiencies of some symmetry tests around an unknown centre

In this paper, some recent and classical tests of symmetry are modified for the case of an unknown centre. The unknown centre is estimated with its α-trimmed mean estimator. The asymptotic behaviour of the new tests is explored. The local approximate Bahadur efficiency is used to compare the tests to each other as well as to some other tests.     

Predicting online gambling self-exclusion: an analysis of the performance of supervised machine learning models

As gambling operators become increasingly sophisticated in their analysis of individual gambling behaviour, this study evaluates the potential for using machine learning techniques to identify individuals who used self-exclusion tools out of a sample of 845 online gamblers, based on analysing trends in their gambling behaviour. Being able to identify other gamblers whose behaviour is similar to those who decided to use self-exclusion tools could, for instance, be used to share responsible gaming messages or other information that aids self-aware gambling and reduces the risk of adverse outcomes. However, operators need to understand how accurate models can be and which techniques work well. The purpose of the article is to identify the most accurate technique out of four highly diverse techniques and to discuss how to deal analytically and practically with a rare event like self-exclusion, which was used by fewer than 1% of gamblers in our data-set. We conclude that balanced training data-sets are necessary for creating effective models and that, on our data-set, the most effective method is the random forest technique which achieves an accuracy improvement of 35 percentage points versus baseline estimates.     

Gambling among Croatian young people: an exploratory study of the relationship between psychopathic traits,risk-taking tendencies and gambling-related problems

The present study investigated the relationship between psychopathic traits, risk-taking tendencies and gambling problem severity and if these associations varied by gender in a community sample of Croatian adolescents (N = 282; 148 males). Results of the regression analyses showed that the Impulsive-Irresponsible behavioural style (YPI-II) and the Grandiose-Manipulative interpersonal style (YPI-GM) were the strongest postdictors of gambling-related problems. Surprisingly, independently of the YPI-II dimension, the Callous-Unemotional traits were negatively associated to gambling-related problems. By, contrast, independently of the psychopathic traits, risk-tendencies were not significant postdictors of gambling problem severity. With respect to gender differences, higher levels of the YPI-II and YPI-GM dimensions were related to more severe gambling-related problems only in males, not in females. Furthermore, while the CU traits exhibited protective features against gambling-related problems in both genders, the effect was stronger for males than for females.     

Shiftwork tolerance and circadian rhythms in oral temperature and heart rate

Abstract

The study aimed at establishing differences in the circadian rhythm parameters of oral temperature and heart rate between three groups of workers matched by age: tolerant shiftworkers with good sleep quality and few psychosomatic and digestive complaints, intolerant shiftworkers with poor sleep quality and more psychosomatic and digestive complaints, and workers who had never worked in shifts. The study was performed at an oil refinery recreation centre where the subjects were isolated for three days. During that period they lived under constant conditions, i.e. their activities, timing and content of meals, ambient temperature and light were controlled. Hourly measurements of oral temperature and heart rate were performed over a 24-h period. The parameters of the physiological rhythms were estimated by means of the COSINA method. Generally, the differences between the groups were low and not statistically significant. The authors could find no difference in the amplitude and phase position between the tolerant shiftworkers unlike other authors. The difference between these results and those of others is likely to be due to the fact that earlier studies were performed in field conditions where many factors that could have masked the results were not controlled for.     

Changing Policy Environments in Europe and the Resilience of the Third Sector

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - In the article, we analyse the impact of changing policy environments on the development of the third sector in Europe....