Quantile estimation and comparing two independent groups with an approach based on percentile bootstrap

Although the most common approach for comparing two independent groups is on the basis of some measure of location, determination of the differences in the tails of the groups is often of interest. In this study, Harrell–Davis estimator, Sfakianakis–Verginis estimators and default quantile estimator of R are used in conjunction with a percentile bootstrap method with the aim of comparing two independent groups via the quantiles, and the relative efficiencies of Harrell–Davis and Sfakianakis–Verginis estimators are compared. General performance of Sfakianakis–Verginis estimators was much better than Harrell–Davis estimator in terms of both saving actual type I error and relative efficiency.     

Supply chain relationship quality and its impact on firm performance

Abstract

This paper examines the impact of supply chain relationship quality (SCRQ) on firm performance (FP) through the mediators of supply chain management processes (SCMP) and supply chain performance (SCP). In the literature, these linkages have been examined separately; in contrast, this study takes a holistic perspective on the antecedents of FP. The model was tested using survey data from manufacturing companies. Variance-based structural equation modelling revealed that both SCMP and SCP lead to FP, unlike SCRQ. On the other hand, SCRQ affects SCMP. Drawing on the resource-based view, consistency in SCRQ can lead to not only efficient and effective supply chain management but also improvements in FP and SCP. This research has practical implications, providing supply chain decision makers with insights on enhancing FP. Supply chain decision makers will be able to benefit from the findings of our study by improving supply chain relationships with supply chain members and ensuring FP. This research also highlights how effective management of SCRQ, SCMP and SCP can provide better FP and a competitive advantage.     

Reactions to cyberbullying among high school and university students

In this study, behavioral and emotional reactions to cyberbullying were investigated by surveying 567 undergraduate-level university students and 211 high school students. Among the study participants, 170 of the undergraduates (29.98%) and 120 of the high school students (56.87%) reported that they had recently been cyberbullied. A four-factor scale with 37 items was used to investigate the behavioral cyberbullying reactions of victimized students. The four factors were revenge, countermeasure, negotiation and avoidance. An additional two-factor scale with 11 items was used to classify victimized students’ emotional reactions as either internalizing or externalizing. Explained variance values of both scales were above 50%, and the factors were found to have acceptable internal consistency coefficients. Behavioral and emotional reactions varied according to gender and school level. Computer self-efficacy and internet use were associated with different reaction types.     

Testing for autocorrelation among common stock returns

We consider the null distribution of autocorrelation coefficients for stock returns when the variance of the returns is infinite. We show that the empirical autocorrelations then tend to zero faster than in the standard case and that they tend, after suitable normalisation, in distribution to a rather complicated nonnormal law. An empirical application to the 14 most busy German stocks reveals that the significance of observed correlations is thereby in general reduced.     

Separating trend and cyclical dynamics in state space models with exogenous inputs

In the present study we compare three state rotation methods in modelling the impact of the US economy on the Finnish economy, i.e. Schur decomposition, eigenvalue analysis and singular value decomposition. Singular value decomposition is seen to provide a robust approximation of the state rotation in most cases studied, irrespective of whether the characteristic roots of the state transition matrix are complex. Thus, singular value decomposition seems to be a viable computational device not only in estimating the system matrices of the state space model, but also in state rotation, as compared to the more involved techniques based on eigenvalue analysis or Schur decomposition.     

DSM-IV and the South Oaks Gambling Screen: diagnosing and assessing pathological gambling in Turkey

The main purpose of this study was to investigate the effectiveness of the DSM-IV diagnostic criteria and the South Oaks Gambling Screen (SOGS) in identifying Turkish pathological gamblers. Fifty-nine subjects participated in the study. The subjects were diagnosed as either pathological gamblers or not (comparison group) through the use of the DSM-IV criteria and were given the Turkish version of the SOGS. Four of the ten DSM-IV criteria were found to be problematic in the diagnosis of Turkish pathological gamblers. The data concerning reliability and validity of the Turkish version of the SOGS suggested that the SOGS can be used as a reliable and valid instrument in identifying Turkish pathological gamblers. Most (16 out of 20) of the items of the SOGS appear to work well in discriminating pathological gamblers from the subjects in the comparison group. In the case of the two DSM-IV criteria and the four SOGS items that failed to discriminate, cultural factors seemed to be responsible for the failure.     

Telling about something that you do not really know: blind people are talking about vision!

In Turkey, the laws which define disability have become increasingly harsh, and require disabled people to be assessed in order to determine ‘how disabled’ they are. For blind people, as for other disabled people, these assessments have real consequences. This article aims to discuss an appealing piece that arose during a project, which has bearing on how disabled people tend to answer these questions. The participants are legally blind adults. We, as sighted researchers, asked totally blind individuals to describe their vision. Interestingly, they all answered this question without hesitation. The paradoxical nature of this question was only realized during the analysis. We requested the participants to talk about something they do not really know. This might be a reflection of our over-visualized world and might be due to our subtle prejudices. This type of questioning not only has implications for research, but also for assessments of disability in Turkey.     

Robust estimation of dynamic fixed-effects panel data models

This paper extends an existing outlier-robust estimator of linear dynamic panel data models with fixed effects, which is based on the median ratio of two consecutive pairs of first-order differenced data. To improve its precision and robustness properties, a general procedure based on higher-order pairwise differences and their ratios is designed. The asymptotic distribution of this class of estimators is derived. Further, the breakdown point properties are obtained under contamination by independent additive outliers and by the patches of additive outliers, and are used to select the pairwise differences that do not compromise the robustness properties of the procedure. The proposed estimator is additionally compared with existing methods by means of Monte Carlo simulations.     

The humanitarian crisis of migration versus the crisis of humanitarianism: current dimensions and challenges for social work practice*

People who comprise today’s mass migrations are the embodiment of an increasingly hurtful planetary interconnectedness between towering inequalities and hegemonies and human lives. The humanitarian crisis has turned into a fundamental crisis of humanitarianism. The crisis of humanitarianism builds up by the state borders increasingly militarized, equipped with one manner or the other of securitization, seeking to externalize the migrating people. Further, the governments seek to institutionalize and spatially segregate the people, whilst the resident population is subjected to programmatic inciting of racism and xenophobia. Racist eurocentrism pictures the West as democratic, and migrant people as non-democratic; it does not distinguish between individuals and political regimes; does not take into consideration the emergency situations from which they flee: it is thus a form of armed humanitarianism. The Balkan countries which were part of the Balkan Refugee route have become prison countries, custodians of the EU border. They conserve the image of the dangerous Balkans and consolidate Balkanism. A complex social work response includes individual, institutional, curricular, and research levels of reflection and intervention.