Sirinapa Aryuyuen, Winai Bodhisuwan and Thidaporn Supapakorn

pp. 483 - 491

Abstract

In this paper, we propose a new zero inflated distribution, namely, the zero inflated negative binomial-generalized
exponential (ZINB-GE) distribution. The new distribution is used for count data with extra zeros and is an alternative for data
analysis with over-dispersed count data. Some characteristics of the distribution are given, such as mean, variance, skewness,
and kurtosis. Parameter estimation of the ZINB-GE distribution uses maximum likelihood estimation (MLE) method. Simulated
and observed data are employed to examine this distribution. The results show that the MLE method seems to have highefficiency for large sample sizes. Moreover, the mean square error of parameter estimation is increased when the zero proportion is higher. For the real data sets, this new zero inflated distribution provides a better fit than the zero inflated Poisson and
zero inflated negative binomial distributions. 

Keywords

• overdispersion
• zero inflated distribution
• count data with extra zeros
• random variate generation
• MLE