Powerful nonparametric statistics to compare k independent ROC curves

The authors deal with the problem of comparing receiver operating characteristic (ROC) curves from independent samples. From a nonparametric approach, they propose and study three different statistics. Their asymptotic distributions are obtained and a resample plan is considered. In order to study the statistical power of the introduced statistics, a simulation study is carried out. The (observed) results suggest that, for the considered models, the new statistics are more powerful than the usually employed ones (the Venkatraman test and the usual area under the ROC curve criterion) in non-uniform dominance situations and quite good otherwise.     

LGBT Studies Without LGBT Studies: Mapping Alternative Pathways in Perú and Colombia

ABSTRACT

Our article tackles gender and sexual diversity scholarship in Colombia and Perú, two countries without institutionalized LGBT studies programs. By analyzing the impact of literary works in Perú and an annual conference in Colombia’s capital, we show how LGBT-related scholarship (and activism) has been advanced in these Andean countries with tactful maneuvering, as they offset contemporary violence—and a strong religious influence. Our comparison allows us to showcase two of the most common ways through which these countries have engaged in LGBT research and activism. This region-centered, dual-country approach underscores the broader need of researching and documenting these efforts.     

Population Structure and the Human Development Index

Social Indicators Research - This paper provides an alternative way of measuring human development that takes explicitly into account the differences in the countries’ population structures....     

Attitude towards career progression in Spanish dual-earner couples: A dyadic approach

This study addresses the relevance of gender roles and perceived gender discrimination against women in attitude towards career progression in heterosexual dual-earner couples. One hundred and thirty-nine wives and their husbands completed the questionnaires independently. From a dyadic data analysis, using the actor-partner interdependence model (APIM), we examined the actor and partner effect. The following findings were made: (a) an actor and partner effect of gender roles in husbands, (b) an actor effect of perceived gender discrimination in wives, and (c) an interaction effect between partner gender roles by actor professional status in wives. Overall, results showed that gender roles and perceived gender discrimination are useful factors in understanding couples’ interdependence in their attitudes towards career progression. Results are discussed in terms of the influence of traditional gender roles in perpetuating inequality between men and women and the relevance of perceived gender discrimination against women in attitude towards career progression.     

Postural analysis of eight university student wheelchair users when performing written exercises in their classroom: a case study in Santiago de Cali, Colombia

In students with physical disabilities, the more energy and time required and invested into finding a good posture, the longer the learning process takes. For this reason, the objective of this study was to characterize the posture in the act of writing of wheelchair users in a classroom. Eight students, (three women) aged 18-40, of some of the main universities of the city of Santiago de Cali participated. An observational field study filming of approximately 10 minutes was done while they took notes in their classes. Posture of the head, trunk, and upper extremities was analyzed with respect to its axis and the type of movement in each joint. The postures were classified depending on the location of support surface finding five different postures in the eight students. In these five postures some biomechanical risk factors, usually present in wheelchair users, are increased when they are associated with those postures. Those associated risk factors are: possible disc spine deformation, muscular stress and causing of pressure ulcer. In conclusion, in four of these five postures a poor interaction among person, task and work desk was observed. Therefore, seven of the eight students in this study were found to have a posture that could be considered risky.     

Going for broke. From desire for illusion and the illusion of desire / De perdidos,al río. Del deseo a la ilusión y la ilusión del deseo

The illusion of control refers to an excessively high expectation of success considering the likelihood of it actually happening. This expectation seems to be modulated by idiosyncratic variables, such as the desire for control. This study aims first to provide evidence regarding the validity of the Spanish Desire for Control Scale and secondly to study the ‘going for broke’ phenomenon. Participants included 92 university students from different colleges, 59 females and 33 males. The results first show that there is enough evidence to validate the Spanish version of the scale and to support its application. Secondly they show that in cases where there is a perception of having nothing left to lose, people risk everything they have, causing a reversal in the outcome pattern in a normal situation.     

The Impacts of Cash Transfers on Subjective Wellbeing and Poverty: The Case of Colombia

Cash transfer programs have been the main social policy in the fight against poverty and inequality in Latin-American countries. This paper analyzes the impacts of the program Más Familias en Acción on the perception of poverty and subjective wellbeing in Colombia. The analyses are based on data from the Encuesta Nacional de Calidad de Vida between 2008 and 2016. Two empirical strategies were compared to account for the lack of randomness in groups of beneficiary and non-beneficiary families: (i) non-experimental designs (linear and nonlinear models with cross-sectional and pooled data); (ii) quasi-experimental designs (Propensity Score Matching and Inverse Probability Weighted Regression Adjustment). The results were robust to the different empirical strategies and emphasized that: (i) transfers increase the perception of food insecurity and subjective poverty; (ii) conditionalities involve positive impacts on different indicators of subjective wellbeing, especially health and education; (iii) general impacts on the perceptions of life are nonsignificant, as a result of divergent impacts on the dimensions of the subjective wellbeing of families.     

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.     

A weighted bootstrap approximation for comparing the error distributions in nonparametric regression

Several procedures have been proposed for testing the equality of error distributions in two or more nonparametric regression models. Here we deal with methods based on comparing estimators of the cumulative distribution function (CDF) of the errors in each population to an estimator of the common CDF under the null hypothesis. The null distribution of the associated test statistics has been approximated by means of a smooth bootstrap (SB) estimator. This paper proposes to approximate their null distribution through a weighted bootstrap. It is shown that it produces a consistent estimator. The finite sample performance of this approximation is assessed by means of a simulation study, where it is also compared to the SB. This study reveals that, from a computational point of view, the proposed approximation is more efficient than the one provided by the SB.     

Bimodal Birnbaum–Saunders distribution with applications to non negative measurements

In this article, we introduce a new extension of the Birnbaum–Saunders (BS) distribution as a follow-up to the family of skew-flexible-normal distributions. This extension produces a family of BS distributions including densities that can be unimodal as well as bimodal. This flexibility is important in dealing with positive bimodal data, given the difficulties experienced by the use of mixtures of distributions. Some basic properties of the new distribution are studied including moments. Parameter estimation is approached by the method of moments and also by maximum likelihood, including a derivation of the Fisher information matrix. Three real data illustrations indicate satisfactory performance of the proposed model.