On the identification of extreme outliers and dragon-kings mechanisms in the upper tail of income distribution

The presence of extreme outliers in the upper tail data of income distribution affects the Pareto tail modeling. A simulation study is carried out to compare the performance of three types of boxplot in the detection of extreme outliers for Pareto data, including standard boxplot, adjusted boxplot and generalized boxplot. It is found that the generalized boxplot is the best method for determining extreme outliers for Pareto distributed data. For the application, the generalized boxplot is utilized for determining the exreme outliers in the upper tail of Malaysian income distribution. In addition, for this data set, the confidence interval method is applied for examining the presence of dragon-kings, extreme outliers which are beyond the Pareto or power-laws distribution.     

Antecedents and Consequences of Marital Satisfaction in an Emirati Sample: A Structural Equation Model Analysis

This study surveyed 1,000 married Emirati men and women to explore a model of marital satisfaction in relation to self-esteem, satisfaction with life, gender-role attitudes, and general health (physical and psychological). The Emirati Marital Satisfaction Scale (EMSS), State Self-Esteem Scale (SSES), Satisfaction With Life Scale (SWLS), the Arabic General Health Questionnaire, and the Sex-Role Egalitarianism Scale were used. Confirmatory factor analysis (CFA) on the EMSS indicated a moderate fit of the data to one factor structure. CFA on SSES and SWLS indicated an adequate fit of the data to the four-factor solution and one factor, respectively. The structural equation model for the EMSS showed that both general health and gender-role attitudes predict marital satisfaction and that marital satisfaction seems to predict the individual’s well-being as measured by life satisfaction and self-esteem. These results are discussed within the context of the United Arab Emirates culture and directions for future research are provided.     

Posterity and population growth: fertility intention among a cohort of Nigerian adolescents

Population growth is probably the greatest global challenge of the twenty-first century and fertility is a central element of this growth. Fertility is a human attribute which depends almost entirely on social, economic, political, cultural and psychological frameworks, making fertility intention an element of what individuals learn from a very young age as part of their socialisation into society. The fundamental significance of socio-psychological, environmental and cultural factors in what adolescents are assimilating on fertility cannot be exaggerated, yet, relevant information is limited. Eight factors deduced from ecological model and theory of planned behaviour were used to predict fertility intention among a cohort of Nigerian adolescents, using cross-sectional design. Mean fertility intention was 4.06 ± 1.34. Age and religion had no effect, but gender did. Self esteem, perceived parental expectation of fertility, attitude towards fertility and peer-related subjective norm are significant predictors. Media and ethnic attitude are insignificant predictors of, but are significantly related to fertility intention. Attitude towards a four-child family and perceived behavioural control yielded insignificant relationships with, and also failed to predict fertility intention. Perceived parental expectation of fertility, an interpersonal factor of the ecological model is the single most important predictor (β = 0.707, R² = 0.506, r = 0.711, and partial r = 0.710). Fertility intention points towards fertility decline, though sluggish and diminutive, thereby failing to reflect the need of Nigeria’s population pyramid to thin out from the base.

     

Emphasizing the experiences of researchers after RCR instructions: Introduction to Responsible Conduct of Research (RCR) in Malaysia

The purpose of this study is to highlight the experiences of individuals who participate in the Responsible Conduct of Research (RCR) training program held at various universities in Malaysia. In response to a mailing request sent to 40 individuals who had undertaken a RCR training program, 15 participants agreed to be interviewed. The results of the study showed that the three main reasons for participating in the training were as follows: anticipation for knowledge gained; personal experience with research misconduct; and establishing a new network of researchers. In terms of the positive effects gained from undertaking the training, the participants highlighted an increased awareness of the issues and problems related to research misconduct; the need to promote integrity in research conduct; a change in the way they conduct their research; and a change in the way they confront and address misconduct. The findings of this study should be valuable for policy makers and those involved in the management of research programs and ethics, as it demonstrated the importance of RCR training in equipping researchers with the necessary knowledge to conduct research responsibly, and to avoid research misconduct.     

Using econometric analysis of willingness-to-pay to investigate economic efficiency and equity of domestic water services in the West Bank

The paper is aimed at providing evidence on economic efficiency, and equity of distribution of domestic water services in the West Bank. The study utilizes the CVM as a means of monetizing public preferences and households’ WTP. In the CVM questionnaire, the dichotomous choice with follow-up debriefing questions format is followed by an open-ended follow-up question was undertaken. A second questionnaire survey was directed to employees from water institutions, which was mainly designed to investigate the reasons behind the full absence of private sector in the provision of water supply. The two samples were selected to ensure a representative samples in accordance with the Palestinian case. The main findings of this paper gauged the WTP with key socioeconomic variables suggested by economic theory and previous CVM studies. These results provide information on economic efficiency and equity of water distribution. The results will allow decision makers to develop new policies that can achieve more efficient and equitable domestic water services.     

Reviewing building construction statistics in Turkey: Stakeholders’ perspective

Construction is one of the industries of strategic economic importance. Governments using their national institutions are involved in the collection of economic statistics, which indicate the state of their economy in the form of an annual time series. However, the completeness and accuracy of these statistics is frequently questioned by the stakeholders within the sector. Therefore there is an increasing need for accurate, manageable and reliable statistics to enable sound analysis of the construction sector. The main purpose of this research is to review building construction statistics in Turkey. The objectives of the review are to 1) engage with users to ascertain their views on the statistics and to identify their needs, and 2) investigate whether the statistics in their present form continue to meet user needs, and identify options for change. As part of the review, a user consultation exercise is carried out to identify whether user needs are met by the statistics, as well as to ascertain users’ views on the European Statistical System (ESS) key dimensions of the quality of the statistics. This review of building construction statistics will facilitate statistical information to be presented in a more comprehensive manner, with sufficient detail, highly reliable in terms of quality and responsive to dynamic changes of the sector (such as inflation and structural adjustment policies).     

Estimation of the population mean and median using truncation-based ranked set samples

In this paper, a new sampling method is suggested, namely truncation-based ranked set samples (TBRSS) for estimating the population mean and median. The suggested method is compared with the simple random sampling (SRS), ranked set sampling (RSS), extreme ranked set sampling (ERSS) and median-ranked set sampling (MRSS) methods. It is shown that for estimating the population mean when the underlying distribution is symmetric, TBRSS estimator is unbiased and it is more efficient than the SRS estimator based on the same number of measured units. For asymmetric distributions considered in this study, TBRSS estimator is more efficient than the SRS for all considered distributions except for exponential distribution when the selection coefficient gets large. When compared with ERSS and MRSS methods, TBRSS performs well with respect to ERSS for all considered distributions except for U(0, 1) distribution, while TBRSS efficiency is higher than that of MRSS for U(0, 1) distribution. For estimating the population median, the TBRSS estimators have higher efficiencies when compared with SRS and ERSS. A real data set is used to illustrate the suggested method.     

Humerical. Results concerning the mle of an exponential parameter used in life testing

It was previously shown that the maximum likelihood estimator 0 of the scale parameter of the exponential distribution is asymptotically normal for type-I censoring. Applicability of the asymptotic normality results for finite samples is studied here by computer simulation for several different normalizing factors and for various levels of censoring. The use of the asymptotic results in statistical problems is illustrated by an example     

On the estimation of the most probable number in a serial dilution experiment

The purpose of this paper is to present some alternative estimates for the 'most probable number' of bacteria in a serial dilution experiment. These estimates are directed to be less biased than the ordinary maximum likelihood estimate. A numerical example illustrates the extent to which the variance and the mean square error of these estimates are generally less than those corresponding to the maximum likelihood estimate.