Check out RSS, or use RSS reader to subscribe this item
Confirmation
Authentication email has already been sent, please check your email box: and activate it as soon as possible.
You can login to My Profile and manage your email alerts.
Sponsored by the Center for Science and Technology Development of the Ministry of Education
Supervised by Ministry of Education of the People's Republic of China
Modeling integer-valued time series based on COM-Poisson INGARCH models
ZHU Fukang *
School of Mathematics, Jilin University, ChangChun 130012
*Correspondence author
#Submitted by
Subject:
Funding:
National Natural Science Foundation of China (No.11001105), Specialized Research Fund for the DoctoralProgram of Higher Education (No.20090061120037)
Frequently count time series exhibits overdispersion, but the opposite phenomenon of underdispersion is well documentedin some situations thus may be encountered in real applications. The INGARCH model is a popular tool for modeling time series of counts.The Poisson and negative binomial models can only deal with overdispersion, and the double Poisson model can treat both of them, but thelatter model has some shortcomings or limitations. The revived COM-Poisson distribution is flexible in modeling a wide range ofoverdispersion and underdispersion with only two parameters, while possessing properties that make it methodologically appealing anduseful in practice. Thus we introduce a new INGARCH model based on this distribution. We give approximate condition for stationarity andexpressions for mean, variance and autocorrelation function. We discuss the maximum likelihood estimation procedure for the parameters of interest.
Keywords:COM-Poisson distribution; Integer-valued GARCH models; Maximum likelihood estimation; Overdispersion; Underdispersion