Estimating equations and diagnostic techniques applied to zero-inflated models for panel data

Abstract

Many practical studies analyze semi-continuous longitudinal data using, for example, ZAIG (Zero-Adjusted Inverse Gaussian) or BEZI (Beta Zero-Inflated) models as marginal distributions. We develop herein estimating equations analogous to Liang and Zeger’s estimating equation of independence and related diagnostic techniques for regression models, with zero-inflated response variable and panel data structure. A simulation study to evaluate some properties of the estimators obtained from the estimating equations and two applications with real data are presented.