A General Class of Estimators for the Linear Regression Model Affected by Collinearity and Outliers

In this article, a general class of estimators for the linear regression model affected by outliers and collinearity is introduced and studied in some detail. This class of estimators combines the theory of light, maximum entropy, and robust regression techniques. Our theoretical findings are illustrated through a Monte Carlo simulation study.     

Robust Bayesian inference in STAR models with neighbourhood effects

In this paper we propose a robust Bayesian procedure of estimation, testing, validation and selection of spatio-temporal autoregressive models (STAR) with neighbourhood effects applied to the appraisal of dwelling prices. The methodology does not depend on asymptotic results and, unlike previously procedures proposed in the literature, takes into account the uncertainty associated to the estimation of the neighbourhood parameters of the model, giving more realism to the analysis. Moreover, a sequential algorithm to elaborate fast on-line forecast, is provided. The methodology is illustrated by means of a practical case of the real estate market of Zaragoza.     

A Generalized Bayes Rule for Prediction

In the case of prior knowledge about the unknown parameter, the Bayesian predictive density coincides with the Bayes estimator for the true density in the sense of the Kullback-Leibler divergence, but this is no longer true if we consider another loss function. In this paper we present a generalized Bayes rule to obtain Bayes density estimators with respect to any α-divergence, including the Kullback-Leibler divergence and the Hellinger distance. For curved exponential models, we study the asymptotic behaviour of these predictive densities. We show that, whatever prior we use, the generalized Bayes rule improves (in a non-Bayesian sense) the estimative density corresponding to a bias modification of the maximum likelihood estimator. It gives rise to a correspondence between choosing a prior density for the generalized Bayes rule and fixing a bias for the maximum likelihood estimator in the classical setting. A criterion for comparing and selecting prior densities is also given.     

Reliability and Validity of the European Portuguese Version of the Social Touch Questionnaire

Social touch is essential for physical and emotional well-being. However, different meanings can be attributed to physical contact during social interactions and may generate bonding or avoidant behaviors. This personal and unique experience is not usually taken into account in health and social care services. The aim of this study is to produce a valid and reliable European Portuguese version of the Social Touch Questionnaire (STQ, Wilhelm et al. in Biol Psychol 58:181–202, 2001. doi: 10.1016/S0301-0511(01)00113-2). The STQ is a self-report questionnaire for adolescents and adults measuring behaviors and attitudes towards social touch. The original version was translated into European Portuguese using a forward-back translation process and its feasibility was examined. To evaluate the psychometric properties, a total of 242 Portuguese university students participated in the study (21.3 ± 3.8 years). The STQ was considered feasible, showed adequate internal consistency (Cronbach’s α = .734), and the test–retest correlation with the STQ items demonstrated a high concordance between the tests over a two-week interval (ICC = .990; n = 50). Validity tests were performed, comparing the total score of the STQ with that of the anxiety and avoidance subscales of the Social Interaction and Performance Anxiety and Avoidance Scale (SIPAAS). A very significant conceptual convergence was confirmed between the STQ and with the SIPAAS-Anxiety (r = .64; p < .0001) and with the SIPAAS-Avoidance (r = .59; p < .0001). The exploratory factor analysis, with Promax rotation, revealed 3 factors: dislike of physical touch, liking of familiar physical touch and liking of public physical touch (Cronbach’s alphas ranged from .68 to .75). Psychometric properties confirmed the adaptation of the STQ to the Portuguese culture. It is a reliable and valid self-report questionnaire and it appears to be a useful tool to assess behaviors and attitudes towards social touch.     

A multiple buyer – supplier relationship in the context of SMEs’ digital supply chain management*

Abstract

By underlining the relevance of the use of ICTs, knowledge sharing and electronic markets for SMEs, it emerges the need for stimulating a debate on digitisation process of supply chain management (SCM). Electronic infrastructure in the service sector are reducing each kind of cost and improving multiply buyer–supplier relationships, facilitating negotiations and transactions. However, since the coordination costs are still high, the use of ICTs is limited. This phenomenon thus attracts the interests of scholars and practitioners. Although it still needs to further investigate. Especially, the optimal use of ICTs within SMEs’ SCM have not been studied yet. Therefore, by leveraging on four proxies: ICTs specialised human resources, knowledge sharing activities, buyer–supplier relationships, adoption of electronic markets this optimal was analysed via structural equation modelling based on a sample of 1254 SMEs operating in the service sector in Italy.     

Perceived Similarity With Gay Men Mediates the Effect of Antifemininity on Heterosexual Men’s Antigay Prejudice

This research examined the hypothesis that heterosexual men’s motivation to differentiate themselves from gay men mediates the relationship between the antifemininity norm of masculinity and antigay prejudice. We assessed masculinity through three concepts: status, thoughness, and antifemininity. Participants then reported their perceived similarity with gay men and their antigay prejudice. The results showed that antifemininity was the best predictor of both perceived similarity and antigay prejudice: The more people endorsed the antifemininity norm, the more they perceived themselves as dissimilar from gay men and showed antigay prejudice. More important, perceived similarity mediated the effect of antifemininity on antigay prejudice. These findings provide direct evidence for the link between masculinity and the motivation to differentiate oneself from gay men, and they suggest that antigay prejudice accomplishes the identity function of maintaining unambiguous gender boundaries.     

A coordinate-free approach to testable hypotheses

Using the coordinate-free version of the linear model and geometrical considerations, the usual definition of testable hyptheses is extended. The concept of partially testable hypotheses is defined in that context. This new approach provides an alternative to the one given by Peixoto (1986), offering some complementary aspects. Simple and direct techniques for testing the new testable hyptheses by means of the classical testing procedure are given.