18 citations · 50 across the 51 of their papers we have counts for
9 papers · 1 filter
Income inequality estimation with gamma mixtures
Roberto Vila, Helton Saulo, Felipe Quintino
This paper studies the estimation of the th Gini index under finite mixtures of gamma distributions. We derive closed-form expressions for the th Gini index and for the expec…
Unbiased estimation of normalized scale-invariant indices under the Gamma distribution
Roberto Vila, Helton Saulo, Felipe Quintino
We introduce a broad class of normalized scale-invariant indices (NSIIs) generated by measurable symmetric homogeneous functions and encompassing several well-known measures, inclu…
Length-biased Birnbaum-Saunders quantile regression with application to water evaporation
Helton Saulo, Tailine Nonato, Roberto Vila
Length-biased distributions arise naturally in environmental, reliability, and economic studies where the sampling mechanism favors larger observational units. In this paper, we pr…
Quantile autoregressive moving average models for ratio-based bounded time series
Helton Saulo, Roberto Vila, Filidor Vilca
This paper proposes the quantile unit-log-symmetric autoregressive moving average (QULS--ARMA) model for bounded time series on the open unit interval . The model extends th…
A multivariate Birnbaum-Saunders autoregressive moving average model with application to air pollution concentration data
Helton Saulo
Fine particulate matter (PM) concentration data are positive, right-skewed series that arise naturally in environmental monitoring and are well described by the Birnbaum-Sa…
The arithmetic-harmonic inequality index: Theory, inference, and finite-sample analysis
Roberto Vila, Helton Saulo
We investigate the arithmetic-harmonic inequality (AHI) index, a bounded and scale-invariant measure of dispersion for positive random variables, defined through the interplay betw…
Unifying the Hoover and Gini indices: Analytical, bias, and computational aspects
Roberto Vila, Helton Saulo, Felipe Quintino
We propose a new family of inequality indices that bridges the Hoover index and the Gini coefficient. The measure is defined as the normalized expected absolute value of a convex c…
On the bias of the Hoover index estimator: Results for the gamma distribution
Roberto Vila, Helton Saulo
The Hoover index is a widely used measure of inequality with an intuitive interpretation, yet little is known about the finite-sample properties of its empirical estimator. In this…
Bias analysis of a linear order-statistic inequality index estimator: Unbiasedness under gamma populations
Roberto Vila, Helton Saulo
This paper studies a class of rank-based inequality measures built from linear combinations of expected order statistics. The proposed framework unifies several well-known indices,…