Advances in estimation by the item sum technique using auxiliary information in complex surveys

To collect sensitive data, survey statisticians have designed many strategies to reduce nonresponse rates and social desirability response bias. In recent years, the item count technique has gained considerable popularity and credibility as an alternative mode of indirect questioning survey, and several variants of this technique have been proposed as new needs and challenges arise. The item sum technique (IST), which was introduced by Chaudhuri and Christofides (Indirect questioning in sample surveys, Springer-Verlag, Berlin, 2013) and Trappmann et al. (J Surv Stat Methodol 2:58–77, 2014), is one such variant, used to estimate the mean of a sensitive quantitative variable. In this approach, sampled units are asked to respond to a two-list of items containing a sensitive question related to the study variable and various innocuous, nonsensitive, questions. To the best of our knowledge, very few theoretical and applied papers have addressed the IST. In this article, therefore, we present certain methodological advances as a contribution to appraising the use of the IST in real-world surveys. In particular, we employ a generic sampling design to examine the problem of how to improve the estimates of the sensitive mean when auxiliary information on the population under study is available and is used at the design and estimation stages. A Horvitz–Thompson-type estimator and a calibration-type estimator are proposed and their efficiency is evaluated by means of an extensive simulation study. Using simulation experiments, we show that estimates obtained by the IST are nearly equivalent to those obtained using “true data” and that in general they outperform the estimates provided by a competitive randomized response method. Moreover, variance estimation may be considered satisfactory. These results open up new perspectives for academics, researchers and survey practitioners and could justify the use of the IST as a valid alternative to traditional direct questioning survey modes.     

A distance-based model for spatial prediction using radial basis functions

In the context of local interpolators, radial basis functions (RBFs) are known to reduce the computational time by using a subset of the data for prediction purposes. In this paper, we propose a new distance-based spatial RBFs method which allows modeling spatial continuous random variables. The trend is incorporated into a RBF according to a detrending procedure with mixed variables, among which we may have categorical variables. In order to evaluate the efficiency of the proposed method, a simulation study is carried out for a variety of practical scenarios for five distinct RBFs, incorporating principal coordinates. Finally, the proposed method is illustrated with an application of prediction of calcium concentration measured at a depth of 0–20 cm in Brazil, selecting the smoothing parameter by cross-validation.     

Creencias y expectativas respecto de la consulta médica: Un análisis de diferencias culturales

Resumen

Se compararon 102 mujeres del área metropolitana de los Angeles divididas en tres grupos según su grado de aculturación (mejico-americanas vs. anglo-americanas). Las variables consideradas se refirieron a las expectativas respecto al médico en contextos terapéuticos. Se consideraron las puntuaciones de tres medidas: La puntuación total en expectativas respecto del médico, las puntuaciones respecto a las expectativas referentes al comportamiento afectivo del médico y las puntuaciones respecto a las expectativas de tratamiento concreto. Los análisis de los resultados y el control de diversas variables tales como edad, gravedad de la enfermedad, etc., muestran la ausencia de diferencias interculturales en lo que las mujeres de la muestra esperan del médico. Si estos resultados se confirman obligarían a identificar más claramente cuándo son importantes las diferencias de aculturación y cuándo no lo son.     

Cuando los delitos son episodios sociales

Resumen

En este trabajo se estudia la percepción del delito desde la perspectiva de los episodios sociales. Los objetivos más importantes de nuestra investigación fueron: a) aislar y comparar las dimensiones que subyacen a la percepción del delito en tres grupos de sujetos: delincuentes institucionalizados, profesionales del sistema penal y grupo de personas no vinculadas al sistema penal; y b) ver si existen diferencias en la percepción de tres de los tipos de delitos establecidos en el Código Penal español. La muestra estuvo compuesta por un total de 272 sujetos, todos ellos varones, procedentes de los tres grupos en estudio. Las puntuaciones dadas por estos sujetos a 22 episodios delictivos fueron sometidas a escalamiento multidimensional. Se obtuvo un espacio multidimensional de cuatro dimensiones para cada uno de los grupos y se constataron diferencias entre ellos. Las puntuaciones de los episodios en cada dimensión permitieron discriminar de forma significativa entre los tres tipos de delitos. Los resultados se discuten integrando la perspectiva de los episodios sociales y la teoría de la atribución.     

A multicriteria decision analysis model for faculty evaluation

In the context of increasing demands for social and financial accountability of universities, the required implementation of transparent faculty evaluation systems constitutes a challenge and an opportunity for universities strategically aligning the activity of academic staff with the university goals. However, despite growing interest in the performance appraisal of faculty, only a few reported studies propose models that cover the full range of academic activities and the models in use are typically based on ad hoc scoring systems that lack theoretical soundness. This article approaches faculty evaluation from an innovative comprehensive perspective. Based on the concepts and methods of multiple criteria value measurement, it proposes a new faculty evaluation model that addresses the whole range of academic activities and can be applied within and across distinct scientific areas, while respecting their specificities. Constructed through a socio-technical process, the model was designed for and adopted by the Instituto Superior Técnico, the engineering school of the Technical University of Lisbon. The model has a two-level hierarchical additive structure, with top-level evaluation areas specified by second-level evaluation criteria. A bottom non-additive third level accounts for the quantitative and qualitative dimensions of academic activity related to each evaluation criterion. The model allows (a) the comparison of the performance of academic staff with performance targets reflecting the strategic policy concerns of university management; (b) the definition of the multicriteria value profile of each faculty member at the top level of the evaluation areas; (c) the computation of an overall value score for each faculty member, through an optimisation procedure that makes use of a flexible system of weights and (d) the assignment of faculty members to rating categories.     

Regional fertility trends in Mozambique

This article increases our knowledge of Mozambique's demography by assessing the nature and magnitude of fertility decline, using the 1980 and 1997 censuses and the 1997 Demographic and Health Survey. Several robust methods, including P/F ratios from census and birth history data, the own-children procedure (census data), and estimates of censored parity progression ratios (adjusted for truncation bias) are used to identify fertility trends. Regional differences in fertility trends are discussed in the light of the proximate determinants of fertility. Fertility decline has started in Mozambique but the magnitude of the decline differs among the three administrative regions in the country. In Southern Region the fertility decline is well established, while in Northern and Central regions the decline is still incipient.     

Improving an upper bound on the size of k-regular induced subgraphs

This paper considers the NP-hard graph problem of determining a maximum cardinality subset of vertices inducing a k-regular subgraph. For any graph G, this maximum will be denoted by α _k (G). From a well known Motzkin-Straus result, a relationship is deduced between α _k (G) and the independence number α(G). Next, it is proved that the upper bounds υ _k (G) introduced in Cardoso et al. (J. Comb. Optim., 14, 455–463, 2007) can easily be computed from υ ₀(G), for any positive integer k. This relationship also allows one to present an alternative proof of the Hoffman bound extension introduced in the above paper. The paper continues with the introduction of a new upper bound on α _k (G) improving υ _k (G). Due to the difficulty of computing this improved bound, two methods are provided for approximating it. Finally, some computational experiments which were performed to compare all bounds studied are reported.     

An Exploratory Study of Clinical Measures Associated with Subsyndromal Pathological Gambling in Patients with Binge Eating Disorder

Both binge eating disorder (BED) and pathological gambling (PG) are characterized by impairments in impulse control. Subsyndromal levels of PG have been associated with measures of adverse health. The nature and significance of PG features in individuals with BED is unknown. Ninety-four patients with BED (28 men and 66 women) were classified by gambling group based on inclusionary criteria for Diagnostic and Statistical Manual-IV (DSM-IV) PG and compared on a range of behavioral, psychological and eating disorder (ED) psychopathology variables. One individual (1.1% of the sample) met criteria for PG, although 18.7% of patients with BED displayed one or more DSM-IV criteria for PG, hereafter referred to as problem gambling features. Men were more likely than women to have problem gambling features. BED patients with problem gambling features were distinguished by lower self-esteem and greater substance problem use. After controlling for gender, findings of reduced self-esteem and increased substance problem use among patients with problem gambling features remained significant. In patients with BED, problem gambling features are associated with a number of heightened clinical problems.     

Reverse logistics drivers: empirical evidence from a case study in an emerging economy

Academic and corporate interest in reverse logistics (RL) has risen considerably in recent years. In this context, the objective of this study was to identify the drivers that enable RL practice in an emerging economy. Firstly, international peer-reviewed publications on RL were used to develop a RL environment framework representing the main RL internal and external influences. Secondly, a case-based research was conducted in a large manufacturing company located in Southern Brazil. The results indicated that the most cited driver in the RL literature, the government and legislation, was not a main influence on the studied company. Environmental legislation is still limited in the country and struggles to provide incentives to increase materials recycling. An economic factor related to materials value recovery was also found to drive the backward flow. Finally, knowledge of the RL driving forces may support industries to better implement and manage reverse flows and to bridge the gap between existing and future solutions for reverse supply chains.     

Managerial and leadership effectiveness as perceived by managers and non-managerial employees in Mexico

Using the critical incident (CI) technique, concrete examples of effective and ineffective managerial behaviour (CIs) were collected from managers and non-managerial employees within private and public sector organizations situated in the north and southeast regions of Mexico. The CIs were content analysed using open, axial and selective coding to identify a smaller number of thematic categories. A total of 38 ‘manager’ and 35 ‘non-managerial employee’ behavioural categories were identified respectively, of which 82.19% (n = 60) were found to be either convergent or polar opposite in meaning. The findings suggest that what behaviourally differentiates effective managers from ineffective managers is perceived, described and defined by Mexican managers and non-managerial employees in much the same way. The study provides new insights on the issue of perceived managerial and leadership effectiveness in Mexico and is a rare example of indigenous managerial behaviour research in a non-Anglo country.