9 citations · 24 across the 54 of their papers we have counts for
13 papers · 2 filters
On the bias of the Gini estimator: Poisson and geometric cases, a characterization of the gamma family, and unbiasedness under gamma distributions
Roberto Vila, Helton Saulo
In this paper, we derive a general representation for the expectation of the Gini coefficient estimator in terms of the Laplace transform of the underlying distribution, together w…
Closed-form parameter estimation for the bivariate gamma distribution: New approaches
Roberto Vila, Helton Saulo
We propose new closed-form estimators for the parameters of McKay's bivariate gamma distribution by exploiting monotone transformations of the likelihood equations. As a special ca…
A transformed-score approach to closed-form and one-step efficient estimation for the beta distribution
Roberto Vila, Helton Saulo, Felipe Quintino +1
Power transformations of beta random variables produce unbiased estimating equations from transformed-model likelihood scores. This construction clarifies the connection between mo…
Two Tunable Gini-Type Measures with U-Statistic Estimation: Theory, Simulation, and an Empirical Application to GDP per Capita in the Americas
Roberto Vila, Helton Saulo
We introduce two families of inequality measures, and , that converge to the classical Gini coefficient as . The tuning parameters and regulate…
On classes of distributions on the unit interval: structural properties and application to inequality data
Roberto Vila, Helton Saulo, Poliana Matos +1
Probability distributions defined on the unit interval are widely used in fields ranging from econometrics to reliability studies. Traditional models such as the beta and Kumaraswa…
Bias in estimating Theil, Atkinson, and dispersion indices for gamma mixture populations
Jackson Assis, Roberto Vila, Helton Saulo
This paper examines the finite-sample bias of estimators for the Theil and Atkinson indices, as well as for the variance-to-mean ratio (VMR), under the assumption that the populati…
Unbiased estimation in new Gini index extensions under gamma distributions, with application to real income data
Roberto Vila, Helton Saulo
In this paper, we introduce two flexible extensions of the classical Gini index, referred to as the extended lower and upper Gini indices. The proposed measures are based on the di…
Closed-form solutions for parameter estimation in exponential families based on maximum a posteriori equations
Roberto Vila, Helton Saulo, Eduardo Nakano
In this paper, we derive closed-form estimators for the parameters of certain exponential family distributions through the maximum a posteriori (MAP) equations. A Monte Carlo simul…
An unbiased estimator of a novel extended Gini index for gamma distributed populations
Roberto Vila, Helton Saulo
In this paper, we introduce a novel flexible Gini index, referred to as the extended Gini index, which is defined through ordered differences between the th and th order stat…
The th Gini index estimator: Unbiasedness for gamma populations
Roberto Vila, Helton Saulo
This paper establishes the theoretical result that the sample th Gini index is an unbiased estimator of the population th Gini index, introduced by Gavilan-Ruiz (2024), for g…
Closed-form formulas for the biases of the Theil and Atkinson index estimators in Gamma distributed populations
Roberto Vila, Helton Saulo
This paper presents an analysis of the Theil and Atkinson index estimators for gamma populations, highlighting the presence of bias in both cases. Theoretical expressions for the b…
On the bias of the Gini coefficient estimator for zero-truncated Poisson distributions
Roberto Vila, Helton Saulo
This paper analyzes the Gini coefficient estimator for zero-truncated Poisson populations, revealing the presence of bias, and provides a mathematical expression for the bias, alon…
Bias in Gini coefficient estimation for gamma mixture populations
Roberto Vila, Helton Saulo
This paper examines the properties of the Gini coefficient estimator for gamma mixture populations and reveals the presence of bias. In contrast, we show that sampling from a gamma…