Asymptotic properties of a stochastic EM algorithm for mixtures with censored data

Weak consistency and asymptotic normality is shown for a stochastic EM algorithm for censored data from a mixture of distributions under lognormal assumptions. The asymptotic properties hold for all parameters of the distributions, including the mixing parameter. In order to make parameter estimation meaningful it is necessary to know that the censored mixture distribution is identifiable. General conditions under which this is the case are given. The stochastic EM algorithm addressed in this paper is used for estimation of wood fibre length distributions based on optically measured data from cylindric wood samples (increment cores).     

Corporate social responsibility disclosure and information asymmetry: the role of family ownership

This study considers the moderating role of family ownership, taking into account information differences between family and minority investors, and corroborates the existence of a two-way relation between CSR disclosure and information asymmetry. Our analysis of international corporate financial data for the period 2003–2009 shows there is an adverse selection effect by which family owners take advantage of insider information, thus attenuating any reduction of information asymmetry achieved by CSR disclosure.     

The Socioeconomic Consequences of Privatization: An Empirical Analysis for Europe

This paper analyses the dynamics of poverty in Italy and compares it with that in France, Spain and the UK. For this purpose, we use transition matrices of entry and exit poverty rates and quantify true state dependence through econometric techniques. The analysis exploits the longitudinal component of EU-SILC for the period 2009–2012. Estimation of dynamic random effects probit models shows that, in all countries, after controlling for individual heterogeneity and initial conditions, there is evidence of true state dependence. In comparative terms, when not accounting for regional disparities within countries, the degree of poverty persistence is highest in Italy and lowest in the UK. If regional effects are considered, the degree of poverty persistence in Italy is of the same order of magnitude as in France and Spain, but higher than in the UK. Our findings suggest that unlike other countries, in Italy regional disparities play an important role in explaining poverty state dependence.     

Time to first significant job for vocational graduates in Spain

In this paper we analyze the transition from vocational education to a first significant job for Spanish young people. The data comes from the Survey on Education and Labor Market Transitions, targeting various collectives who finished their non-university studies. Discrete duration models are estimated to identify the determinants of the time-to-first significant job. The main results show that, contrary to what is expected, there are no significant differences for students graduating in intermediate or in advanced vocational training. Nonetheless, vocational education is characterized by a high specialization by gender, which is translated into differences in the transition to employment. Furthermore, previous professional experience in precarious jobs does not improve access to quality employment, whereas internships performed within studies, when evaluated by the young as satisfactory, have a positive impact. Other subjective aspects, such as a high value assigned to work or family or a priority focused on achieving a stable job lead to a smoother school-to-work transition.     

Interrupting a joke validates thoughts and polarizes attitudes towards a recycling company / La interrupción de un chiste puede potenciar su efecto de validación del pensamiento y cambiar las actitudes hacia una empresa de reciclaje

Positive emotions can validate either positive or negative thoughts. Previous research has demonstrated that people use their thoughts more when they recall past episodes of happiness and when they are induced to smile. This study was designed to evaluate whether a new induction of a happy mood (a joke) can influence thought use in response to a persuasive proposal. Two versions of the same joke were compared: a version that included an interruption before the punchline and another that did not include an interruption at that point. The aim was to examine whether this interruption increased or decreased the use of previously generated thoughts towards a persuasive communication. The results indicated that the participants who were interrupted before the punchline relied more on their own thoughts in forming their attitudes than did those who were in the control group. In consequence, an interruption during a pleasant experience (e.g., a joke) increased persuasion when thoughts were positive but decreased persuasion when thoughts were negative.     

A multivariate uniformity test for the case of unknown support

A test for the hypothesis of uniformity on a support S⊂ℝ ^d is proposed. It is based on the use of multivariate spacings as those studied in Janson (Ann. Probab. 15:274–280, 1987). As a novel aspect, this test can be adapted to the case that the support S is unknown, provided that it fulfils the shape condition of λ-convexity. The consistency properties of this test are analyzed and its performance is checked through a small simulation study. The numerical problems involved in the practical calculation of the maximal spacing (which is required to obtain the test statistic) are also discussed in some detail.     

The Bootstrap and Kriging Prediction Intervals

Kriging is a method for spatial prediction that, given observations of a spatial process, gives the optimal linear predictor of the process at a new specified point. The kriging predictor may be used to define a prediction interval for the value of interest. The coverage of the prediction interval will, however, equal the nominal desired coverage only if it is constructed using the correct underlying covariance structure of the process. If this is unknown, it must be estimated from the data. We study the effect on the coverage accuracy of the prediction interval of substituting the true covariance parameters by estimators, and the effect of bootstrap calibration of coverage properties of the resulting 'plugin' interval. We demonstrate that plugin and bootstrap calibrated intervals are asymptotically accurate in some generality and that bootstrap calibration appears to have a significant effect in improving the rate of convergence of coverage error.     

Associational Performance: The Influence of Cohesion, Decision-Making, and the Environment

The importance of associations in contemporary democratic societies is out of the question. Still, there is a need for a new approach that considers them as a specific and singular organization type, different from business firms and government agencies. There is also a need to evaluate their performance. Based on case studies and diverse theoretical insights, this article lays out some criteria for assessing the effects on associational performance of cohesion, decision-making and relation to environment.