MOMENT ESTIMATION IN THE CLASS OF BISEXUAL BRANCHING PROCESSES WITH POPULATION–SIZE DEPENDENT MATING

This paper concerns the estimation of the offspring mean vector, the covariance matrix and the growth rate in the class of bisexual branching processes with population‐size dependent mating. For the proposed estimators, some unconditional moments and some conditioned to non‐extinction are determined and asymptotic properties are established. Confidence intervals are obtained and, as illustration, a simulation example is given.     

Characterization of discrete populations through conditional expectations of order statistics

In this paper we give some properties of the expected values of any order statistic when one of its adjacent order statistics is known (order mean function) from a sequence of sizen of independent and identically distributed random variables with discrete distribution. Furthermore, we obtain the explicit expressions of the distribution from these order mean functions, and finally, we show the necessary and sufficient conditions for any real function to be an order mean function. We also add some examples of characterization of discrete distributions from the order mean functions. Partially supported by Consejería de Cultura y Educación (C.A.R.M.), under Grant PIB 95/90.     

The Decent Work Questionnaire: Development and validation in two samples of knowledge workers

This research develops a Decent Work Questionnaire (DWQ) to measure workers’ perceptions of decent work. Current measurements of decent work are almost completely lacking at the individual worker level of analysis, and this study contributes to filling the gap. The authors designed their DWQ based on the substantive elements used by the ILO in its Decent Work Agenda, with the final 31‐item version of the DWQ yielding seven factors related to decent work. Showing good reliability coefficient values and good convergent and discriminant validity, this DWQ could open up new avenues for empirical studies on the concept of decent work.     

Violent behaviour,victimization, self-esteem and physical activity of Spanish adolescents according to place of residence: a structural equation model / Conducta violenta,victimización,autoestima y actividad física de adolescentes españoles en función del lugar de residencia: un modelo de ecuaciones estructurales

This study aims to establish and verify an explanatory model for aggressive behaviour, self-esteem, victimization and physical activity in adolescents, and to use this explanatory model to analyse the association of place of residence with these variables. This research analysed 2,273 adolescents from the province of Granada (Spain) using the questionnaires Violent Behaviour at Schools, School Victimization Scale and Global Self-Esteem Scale. An analysis was carried out using structural equations. Results showed that relational and overt aggressiveness are related to self-esteem, victimization and physical activity. Furthermore, relational aggressiveness showed a stronger association with victimization and low self-esteem in adolescents who live in residential care. In addition, overt aggressiveness showed a stronger association with self-esteem in adolescents who live in family homes. Thus, exclusion and social rejection among peers have a greater impact on the victimization of young people who live outside of the family context.     

The role of intercultural,scientific and technological openness on innovation in European regions

This paper analyses the importance of openness for innovation in European regions. Openness is understood from a double angle: intercultural and scientific & technological. Our hypothesis is that each type of openness brings different kinds of knowledge into the regions and results on a different innovation output. S&T openness brings analytical forms of knowledge whilst intercultural openness brings tacit ones. Our results confirm this relationship as S&T openness shows a significant impact on patent activity, but not when a broader innovation indicator is used. Intercultural openness is highly significant when measuring innovation by a broader index and much less when measured by patents.     

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.     

Focused estimation for noisy and small data sets: a Bayesian minimum expected loss estimator approach

Central to many inferential situations is the estimation of rational functions of parameters. The mainstream in statistics and econometrics estimates these quantities based on the plug‐in approach without consideration of the main objective of the inferential situation. We propose the Bayesian Minimum Expected Loss (MELO) approach focusing explicitly on the function of interest, and calculating its frequentist variability. Asymptotic properties of the MELO estimator are similar to the plug‐in approach. Nevertheless, simulation exercises show that our proposal is better in situations characterised by small sample sizes and/or noisy data sets. In addition, we observe in the applications that our approach gives lower standard errors than frequently used alternatives when data sets are not very informative.     

Efficacy of Cyberbullying Prevention on Somatic Symptoms—Randomized Controlled Trial Applying a Reasoned Action Approach

The theory of reasoned action (ToRA) has been proposed as a framework for cyberbullying prevention design, targeting attitudes and norms. In this study effects of a long (10 weekly sessions) and a short (one day, four sessions) cyberbullying prevention program based on the ToRA were compared with a control group over 9 months. Longitudinal data from 722 students (mean age = 13.36) on cyberbullying, somatic symptoms, attitudes, and norms were analyzed within a structural equation model. Participation in the long intervention group significantly reduced cyberbullying (d = ?0.584) and somatic symptoms (d = ?0.316). No between‐group differences emerged for attitudes and norms. Developmental trajectories and associations were found to be as suggested by ToRA in both cross‐sectional and change‐score analyses.