Quasi-binomial zero-inflated regression model suitable for variables with bounded support

J Appl Stat. 2019 Dec 26;47(12):2208-2229. doi: 10.1080/02664763.2019.1707517. eCollection 2020.

Abstract

In recent years, a variety of regression models, including zero-inflated and hurdle versions, have been proposed to explain the case of a dependent variable with respect to exogenous covariates. Apart from the classical Poisson, negative binomial and generalised Poisson distributions, many proposals have appeared in the statistical literature, perhaps in response to the new possibilities offered by advanced software that now enables researchers to implement numerous special functions in a relatively simple way. However, we believe that a significant research gap remains, since very little attention has been paid to the quasi-binomial distribution, which was first proposed over fifty years ago. We believe this distribution might constitute a valid alternative to existing regression models, in situations in which the variable has bounded support. Therefore, in this paper we present a zero-inflated regression model based on the quasi-binomial distribution, taking into account the moments and maximum likelihood estimators, and perform a score test to compare the zero-inflated quasi-binomial distribution with the zero-inflated binomial distribution, and the zero-inflated model with the homogeneous model (the model in which covariates are not considered). This analysis is illustrated with two data sets that are well known in the statistical literature and which contain a large number of zeros.

Keywords: 62A05; 62F03; Fit; quasi binomial distribution; score test; zero-inflated.

Grants and funding

EGD was partially funded by grant ECO2013-47092 (Ministerio de Economía y Competitividad, Spain) and ECO2017-85577-P (Ministerio de Economía, Industria y Competitividad. Agencia Estatal de Investigación). ECO2017-85577-P, Emilio Gómez-Déniz is grateful for support received from MINEDUC-UA project, code ANT1755, since part of this paper was written while he was visiting the University of Antofagasta in 2019.