Statistics in Latin America

Statistics is a relatively new discipline in Latin America. At present only sparse information is available about the state of the statistical profession in Latin America. We present and summarize the available information about the job market; training, education, and research; professional societies and their activities; and so forth. We also share our hopes, concerns, and suggestions for the future.     

An Approximate Closed Form Solution for a Quadratic Dose–Response Model*

The quadratic dose–response model is often used in radiobiology studies. Since the model is nonlinear, the least squares estimators of the parameters of the model are determined by an iterative procedure. We give a simple closed form approximation for estimating the parameters of the model.     

Bayesian modeling of university first-year students' grades after placement test

University first-year students grades are naturally correlated with the scores obtained at placement tests. Often this characteristic leads the university grades in the first exams to be asymmetrically distributed. Motivated by the analysis of grades of the basic Statistics examination of first-year students, we discuss informative priors for the shape parameter of the skew-normal model, a class of distribution which account for several degree of asymmetry. Our proposed prior leads to closed-form full-conditional posterior distributions, particularly useful in Markov Chain Monte Carlo simulation. A Gibbs sampling algorithm is discussed for the joint vector of parameters and the method is applied to a real data set from the School of Economics, University of Padua, Italy. Our analysis reveals that the correlation between the placement test and the grades of first-year students leads to a measurable positive skewness of the distribution of the university grades.     

Mean and median bias reduction in generalized linear models

Statistics and Computing - This paper presents an integrated framework for estimation and inference from generalized linear models using adjusted score equations that result in mean and median bias...     

Beyond solidarity and losses in aid: strategic approaches towards adversity

Natural adversity elicits public policy reactions in accordance with its negative impact; aid actions are expectedly seen as altruistically driven. This article is based on interviews with experts from NGOs and public emergency response agencies. It debates the paradoxical potentialities that may arise in post‐disaster situations. Topics discussed include: factors surpassing altruism, mass media as a solidarity regulator tool, conflicts between what is understood internationally and what may, in fact, be adopted at the local level, and strategies to internalise resources. Conclusions recognise potentialities as concrete assets for policy makers, but suggest we do not yet possess the ability to strategically identify them as unique and positive opportunities.     

Diagnostics for glms with linear inequality parameter constraints

This paper proposes an iterative process, that can be implemented using GLIM, for fitting generalized linear models with linear inequality parameter constraints, when the maximum likelihood estimates exist and are unique. A one-step estimate is also introduced and some diagnostic measures are obtained. Finally an example is given for illustration.