Sensitivity Analysis in Gaussian Bayesian Networks Using a Divergence Measure

This article develops a method for computing the sensitivity analysis in a Gaussian Bayesian network. The measure presented is based on the Kullback–Leibler divergence and is useful to evaluate the impact of prior changes over the posterior marginal density of the target variable in the network. We find that some changes do not disturb the posterior marginal density of interest. Finally, we describe a method to compare different sensitivity measures obtained depending on where the inaccuracy was. An example is used to illustrate the concepts and methods presented.     

Gaussian Markov random field spatial models in GAMLSS

This paper describes the modelling and fitting of Gaussian Markov random field spatial components within a Generalized AdditiveModel for Location, Scale and Shape (GAMLSS) model. This allows modelling of any or all the parameters of the distribution for the response variable using explanatory variables and spatial effects. The response variable distribution is allowed to be a non-exponential family distribution. A new package developed in R to achieve this is presented. We use Gaussian Markov random fields to model the spatial effect in Munich rent data and explore some features and characteristics of the data. The potential of using spatial analysis within GAMLSS is discussed. We argue that the flexibility of parametric distributions, ability to model all the parameters of the distribution and diagnostic tools of GAMLSS provide an ideal environment for modelling spatial features of data.     

The impacts of the food,fuel and financial crises on poor and vulnerable households in Nigeria: A retrospective approach to research inquiry

This article examines the impacts of the financial, food and fuel crises on poor and vulnerable households in two states of Nigeria: Lagos and Kano. It uses retrospective household‐level data to analyze the impacts of induced price variability on household welfare. The results indicate that aggregate shocks have significant adverse effects on household consumption, schooling and child labour decisions, with a degree of impact heterogeneity across regions and rural and urban areas of the country. We find that the coping strategies adopted by the poor to deal with the short‐term effects of the crises can lock households in a low‐income equilibrium or poverty trap. Provided that covariate shocks exacerbate these effects, they become central for policy design.     

The Role of Stakeholders in the Efficiency of Nonprofit Sports Clubs

This article analyzes the efficiency levels of nonprofit sports clubs through the data envelopment analysis methodology and specifically evaluates how efficient and inefficient clubs perceive the distinct contribution of stakeholders in attaining their respective levels of output efficiency. The results distinguish the varying levels of efficiency between such clubs and highlight significant differences in the roles of the local government and of associations and federations in attaining these efficiency levels. The study further suggests best practices that can be adopted by officials at inefficient clubs toward reducing or eliminating their shortfalls in efficiency.     

Context of First Same‐Sex Condom Use and Nonuse in Young Black Gay and Bisexual Males

Despite high human immunodeficiency virus (HIV) rates among young Black men who have sex with men (YBMSM), there are limited data about condom use during first same‐sex (FSS). This study sought to understand socio‐contextual factors of 50 YBMSM aged 15–19 years that influenced condom use during FSS. Condom use was influenced by individual, partner, and community factors. Individual factors—recent illness or sexually transmitted infections (STI)—prompted condom use, while frequent HIV testing prompted nonuse. Partner factors—proactive encouragement from partners—prompted condom use, while trust and condom discomfort prompted nonuse. Larger community factors—such as presence of females—were key for use, while limited sexual health information combined with peers who discouraged condoms prompted nonuse. A multilevel approach may be useful in developing sexual health programming for these young men.     

Small-Sample Comparisons for Goodness-of-Fit Statistics in One-Way Multinomials with Composite Hypotheses

The small-sample behaviour of power-divergence goodness-of-fit statistics with composite hypotheses was evaluated with multinomial models of up to five cells and up to three parameters. Their performance was assessed by comparing asymptotic test sizes with exact test sizes obtained by enumeration in the near right tail, where 1-?∈?(0.90,?0.95], and in the far right tail, where 1-?∈?(0.95,?0.99]. The study addressed all combinations of power-diparse JAS312HH01.sgmvergence estimates of indices ν?∈?{-1/2,?0,?1/3,?1/2,?2/3,?1,?3/ 2} and power-divergence statistics of indices λ?∈?{-1/2,?0,?1/3,?1/2,?2/3,?1,?3/2}. The results indicate that the asymptotic approximation is sufficiently accurate (by the criterion that the average exact size is no larger than ±10% of the nominal asymptotic test size) in the near right tail when ν=0 and λ=1/2, and in the far right tail when ν=0 and λ=1/3, in both cases providing that the smallest expectation in the composite hypothesis exceeds 5. The only exception to this rule is the case of models that render a near-equiprobable composite hypothesis on the boundaries of the parameter space, where average exact sizes are usually quite different from nominal sizes despite the fact that the smallest expectation in these conditions is usually well above 5.     

Peru's coming baby boomlet

There are grounds for reconsidering the United Nations' population projections for Peru. These projections assume that fertility will continue to decline after 1990 in a smooth and uninterrupted manner, but they ignore several factors related to recovery from the economic and political crises of the 1980s that could significantly alter the pace of decline. The alternative projections we present consider the possibility that Peru's fertility decline will temporarily slow. This alternative hypothesis is conservative in the sense that increases in birth rates are not anticipated, but substantial differences in population size and age structure materialize nonetheless. Moreover, these differences have important implications for future planning in terms of the number of children needing primary health care and education and the number of young adults seeking first-time employment.The authors are grateful to Maryann Belanger, Luis Rosero-Bixby, and Anne Marie Wills for helpful comments, to Wayne Appleton for computer support, and to Terence Kelly for graphics design.     

Atribucion,Exito en la Tarea y Expectativas del Rol Sexual: Una Vision Critica del Modelo de Deaux

Resumen

Se presentan dos investigaciones en las que se estudian el efecto del sexo del sujeto, el sexo de la persona estímulo y el tipo de tarea sobre las atribuciones causales de éxito. En el estudio 1, a los sujetos experimentales se les describe una persona estímulo, hombre o mujer, que realiza una tarea (oposiciones) típicamente masculina o femenina. El estudio 2 es idéntico al anterior salvo en la forma de presentar el tipo de tarea. Los resultados obtenidos no apoyan el modelo de Deaux (1976) que ha sido adoptado por muchos autores, pero sugiere, en cambio, otras líneas de investigación de las atribuciones causales de éxito en la tarea.     

‘There is Nothing Here for Us..!’ How Girls Create Meaningful Places of Their Own Through Movement

This article focuses on how girls create places of meaning and opportunity through collective movement. It is based on an ethnographic study of the everyday experiences and mobility of 10–13 year old girls living in a suburb of Copenhagen, Denmark. 1 The girls ventured for a sense of freedom and a ‘place of their own’ to pursue their interests and social relationships. For some girls the creation of places where they felt ‘at home’ would entail breaking rules and transgressing spatial boundaries set by adults.