On the estimation of the Lorenz curve under complex sampling designs

Statistical Methods & Applications - This paper focuses on the estimation of the concentration curve of a finite population, when data are collected according to a complex sampling design with...     

FDI Contribution to Transition Development: Slovakia versus Slovenia

In general, scholars consider Foreign Direct Investment (FDI) as an important factor of development in transition economies, which are changing from former socialist economic forms to more recent capitalist ones. A typical, and very much quoted example, to that regard, is nowadays China. The opinion goes that FDI brings two badly needed elements to the input economic environment: capital and know-how. From the opposite point of view, also capital and knowledge are looking for such environments, because they find there cheap production factors to be mobilized, in order to get higher investment yields. But is such a simple equation entirely true? Examples can be found of countries, which were able to develop with less FDI, and predominantly by domestic efforts, for instance, Japan. The paper tries to find answers to this question not only theoretically, but also by taking into consideration examples from the field. Two transition economies Slovakia and Slovenia, also with similar names, have been taken into consideration and studied, which permitted to draw some interesting answers to the question formulated initially.     

Volunteer Motivation and Organizational Climate: Factors that Promote Satisfaction and Sustained Volunteerism in NPOs

Keeping volunteers committed and engaged is one of the toughest challenges for NPOs. The aim of the present study is to investigate the individual and organizational factors that promote volunteer satisfaction and, vice versa, foster intentions to quit. Two hundred forty-seven volunteers operating in four different NPOs were asked to fill in a self-report questionnaire that aimed to explore their motivations to volunteer, their degree of satisfaction and their perception of the organizational climate in the NPO they worked with, in addition to providing details of the activities which they were involved in. Results showed that the organizational climate mediates the relationship between autonomous motivation and satisfaction, as well as that between external motivation and intentions to leave an organization.     

The Photovoltaic Market Facing the Challenge of Organic Solar Cells: Economic and Technical Perspectives

Solar cells are gaining more interest in recent times as a possible technological solution to improve energy production whilst reducing its environmental impact. The majority of the market is still dominated by first generation solar cells made of single crystal or poly-crystalline silicon solar cells. Silicon technology has reached an high standard efficiency. However, silicon technology needs a very pure material that means high cost in dollar per watt. In order to improve the production of solar power, governments have started big economical interventions, like the feed-in tariff. The advancement of technology, especially the nano-technological revolution, is bringing the attention to another generation of solar cells, hybrid/organic solar cells like Dye Solar Cells, which reduce the costs and suggest the possibility of a mass production of solar modules without the need of public funds.     

More Powerful Control of the False Discovery Rate Under Dependence

In a breakthrough paper, Benjamini and Hochberg (J Roy Stat Soc Ser B 57:289–300, 1995) proposed a new error measure for multiple testing, the FDR; and developed a distribution-free procedure to control it under independence among the test statistics. In this paper we argue by extensive simulation and theoretical considerations that the assumption of independence is not needed. Along the lines of (Ann Stat 32:1035–1061, 2004b), we moreover provide a more powerful method, that exploits an estimator of the number of false nulls among the tests. We propose a whole family of iterative estimators that prove robust under dependence and independence between the test statistics. These estimators can be used to improve also classical multiple testing procedures, and in general to estimate the weight of a known component in a mixture distribution. Innovations are illustrated by simulations.     

On the Methodological Framework of Composite Indices: A Review of the Issues of Weighting,Aggregation, and Robustness

Social Indicators Research - In recent times, composite indicators have gained astounding popularity in a wide variety of research areas. Their adoption by global institutions has further captured...     

Joint analysis of occurrence and time to stability after entrance into the Italian labour market: an approach based on a Bayesian cure model with structured stochastic search variable selection

Precarious employment is a serious social problem, especially in those countries, such as Italy, where there are limited benefits from social security. We investigate this phenomenon by analysing the initial part of the career of employees starting with unstable contracts for a panel of Italian workers. Our aim is to estimate the probability of getting a stable job and to detect factors influencing both this probability and the duration of precariousness. To answer these questions, we use an ad hoc mixture cure rate model in a Bayesian framework.     

Kinematic analysis of post office employees' workstations

This study analyzed a post office clerk's tasks, comparing two workstation models. The clerk was facing the client in one, and seated at 45 degrees to the counter in the other. We analyzed the most frequent tasks and those presenting the most critical points: 1) payment of a postal order; 2) accepting a registered letter, breaking them down into subtasks. We used an optoelectronic system for kinematic analysis, and calculated the range of motion of the trunk and arms in the three spatial planes. The 45( position required less torsion of the trunk and head when using the printer, placed to the left of the employee. A larger worktop improved the workstation, leaving more room for equipment and allowing the worker to sit frontally to the monitor. However, this solution involved a shorter distance between the worker and the client with longer extension of the shoulder and elbow and less trunk flexion. These findings suggested a modification in the layout that shortens the distance between the worker and client.     

Quantile regression for longitudinal data based on latent Markov subject-specific parameters

We propose a latent Markov quantile regression model for longitudinal data with non-informative drop-out. The observations, conditionally on covariates, are modeled through an asymmetric Laplace distribution. Random effects are assumed to be time-varying and to follow a first order latent Markov chain. This latter assumption is easily interpretable and allows exact inference through an ad hoc EM-type algorithm based on appropriate recursions. Finally, we illustrate the model on a benchmark data set.