Unit Roots: Bayesian Significance Test

The unit root problem plays a central role in empirical applications in the time series econometric literature. However, significance tests developed under the frequentist tradition present various conceptual problems that jeopardize the power of these tests, especially for small samples. Bayesian alternatives, although having interesting interpretations and being precisely defined, experience problems due to the fact that that the hypothesis of interest in this case is sharp or precise. The Bayesian significance test used in this article, for the unit root hypothesis, is based solely on the posterior density function, without the need of imposing positive probabilities to sets of zero Lebesgue measure. Furthermore, it is conducted under strict observance of the likelihood principle. It was designed mainly for testing sharp null hypotheses and it is called FBST for Full Bayesian Significance Test.     

A class of bivariate regression models for discrete and/or continuous responses

ABSTRACT

A general class of models for discrete and/or continuous responses is proposed in which joint distributions are constructed via the conditional approach. It is assumed that the distributions of one response and of the other response given the first one belong to exponential family of distributions. Furthermore, the marginal means are related to the covariates by link functions and a dependency structure between the responses is inserted into the model. Estimation methods, diagnostic analysis and a simulation study considering a Bernoulli-exponential model, a particular case of the class, are presented. Finally, this model is used in a real data set.     

SMPD Scenarios of Spatial Distribution of Human Population in China

Three scenarios of spatial distribution of human population in China are developed in the years 2010 and 2020, respectively by means of the method of surface modeling of population distribution (SMPD). Each one of the SMPD scenarios is defined as a plausible alternative future under particular assumptions of elevation, water system, net primary productivity (NPP), urbanization, transport infrastructure development, and population growth. The SMPD scenarios show that if population could freely migrate within the whole China, the balanced ratios of population in the western region, the middle region and the eastern region to total population in the whole China would be 16%, 33% and 52%, respectively.     

Structural equation modeling with time dependence: an application comparing Brazilian energy distributors

AStA Advances in Statistical Analysis - This study proposes a Bayesian structural equation model (SEM) to explore financial and economic sustainability indicators, considered by the Brazilian...     

Rolling with the shakes: an insight into teenagers’ perceptions of recovery after the Canterbury earthquakes

Natural disasters are harmful worldwide events that inflict multiple psychosocial impacts on disaster-exposed individuals. A significant proportion of affected individuals are teenagers (13–18 years old) who, compared with adults, have been historically overlooked in disaster research. The literature is particularly sparse concerning teenagers’ recovery from natural disasters, specifically what recovery means to them and the contributing factors towards their positive recovery. Therefore, the aim of the current study was to gain deeper insight into this largely unexplored area by conducting five focus groups with teenagers (16–18 years) who experienced at least one of the Canterbury, New Zealand, earthquakes since and including the initial September 2010 earthquake. This study directly asked teenagers about their recovery over the three years after the initial earthquakes, with data being analysed using thematic analysis. Two main themes were identified: (1) perceptions of recovery, with three sub-themes (i) knowledge and being less frightened, (ii) talking about the earthquakes and (iii) shift in perspectives; and (2) contributing factors to recovery, with three sub-themes (i) participation in the community response, (ii) returning to school and (iii) the rebuild of Christchurch. These factors provide insight into how we can better support the recovery process for disaster-exposed teenagers to reduce long-term distress.     

Accidents related to the use of products and services in the city of São Luis, Brazil

This article presents a study on the accidents related to the use of products and services, as recorded at two emergency hospitals at the city S?o Luís, Brazil. The goal of the study was to evaluate the main types and causes of unintentional accidents as well as the more frequent injuries for further improvement of products and services. The study evaluated the victims profile (gender and age), the circumstances (activity, local and time) that lead to the accidents and the type of resulted injury. Non-parametric statistics showed that 83.64% of the accidents were related to products (57.6% of them being consumer products) and 8.6% are related to maintenance services. 57.6% of the victims were children under 15 years old, and 58.4% were male. 50.2% of accidents occurred at home, more often (44.7%) in the afternoon. The most common injury was musculoesqueletal (48.6%), 49.0% being cranioencephalic trauma and 15.2% fractures.     

Development and validation of the Measure of Initial Attraction (MIA) / Elaboración y validación de la Medida de Atracción Inicial (MAI)

Unilateral Initial Attraction (UIA) is a first unilateral awareness towards an unknown person and can be the starting point of an interest in voluntarily initiating an interaction or relationship. In order to create a measure tapping this feeling, Study 1 asked individuals to indicate attributes characterizing UIA (Phase 1), and to rate their centrality (Phase 2). These were used to develop the Measure of Initial Attraction (MIA) comprising one component of arousal and another of unilateral interest. While the former is shared with the love construct, the latter differentiates from measures of passion. The MIA proved to be a valid and reliable instrument with the capacity to discriminate UIA across different relationships (Study 2) and targets (Study 3), with good convergent validity (Study 3). Results are discussed within the framework of personal relationships.     

Truncated location-scale non linear regression models

We present a class of truncated non linear regression models for location and scale where the truncated nature of the data is incorporated into the statistical model by assuming that the response variable follows a truncated distribution. The location parameter of the response variable is assumed to be modeled by a continuous non linear function of covariates and unknown parameters. In addition, the proposed model also allows for the scale parameter of the responses to be characterized by a continuous function of the covariates and unknown parameters. Three particular cases of the proposed models are presented by considering the response variable to follow a truncated normal, truncated skew normal, and truncated beta distribution. These truncated non linear regression models are constructed assuming fixed known truncation limits and model parameters are estimated by direct maximization of the log-likelihood using a non linear optimization algorithm. Standardized residuals and diagnostic metrics based on the cases deletion are considered to verify the adequacy of the model and to detect outliers and influential observations. Results based on simulated data are presented to assess the frequentist properties of estimates, and a real data set on soil-water retention from the Buriti Vermelho River Basin database is analyzed using the proposed methodology.     

Assessment of the needs of youth in residential care: Development and validation of an instrument

This article presents the development of a Residential Care Youth Needs Assessment (RCYNA) instrument. In two studies, initial evidence regarding the RCYNA psychometric properties was obtained using a sample of youth in residential care. Results show adequate levels of content and face validity, reliability and concurrent validity.