Moment properties and quadratic estimating functions for integer-valued time series models
Recently, there has been a growing interest in integer-valued time series models. In this paper, using a martingale difference, we prove a general theorem on the moment properties of a class of integer-valued time series models. This theorem not only contains results in the recent literature as sp...
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College of Statistical and Actuarial Sciences, University of Punjab
2018
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iium-650372018-11-01T08:38:11Z http://irep.iium.edu.my/65037/ Moment properties and quadratic estimating functions for integer-valued time series models Mohamad, Nurul Najihah Mohamed, Ibrahim Haur, Ng Kok Q Science (General) QA Mathematics Recently, there has been a growing interest in integer-valued time series models. In this paper, using a martingale difference, we prove a general theorem on the moment properties of a class of integer-valued time series models. This theorem not only contains results in the recent literature as special cases but also has the advantage of a simpler proof. In addition, we derive the closed form expressions for the kurtosis and skewness of the models. The results are very useful in understanding the behaviour of the processes involved and in estimating the parameters of the models using quadratic estimating functions (QEF). Specifically, we derive the optimal function for the integer-valued GARCH (p, q) known as INGARCH (p, q) model. Simulation study is carried out to compare the performance of QEF estimates with corresponding maximum likelihood (ML) and least squares (LS) estimates for the INGARCH (1,1) model with different sets of parameters. Results show that the QEF estimates produce smaller standard errors than the ML and LS estimates for small sample size and are comparable to the ML estimates for larger sample size. For illustration, we fit the 108 monthly strike data to INGARCH (1, 1) models via QEF, ML and LS methods, and show the applicability of QEF method in practice. College of Statistical and Actuarial Sciences, University of Punjab 2018 Article PeerReviewed application/pdf en http://irep.iium.edu.my/65037/1/65037_Moment%20Properties%20and%20Quadratic%20Estimating%20Functions%20_article.pdf application/pdf en http://irep.iium.edu.my/65037/2/65037_Moment%20Properties%20and%20Quadratic%20Estimating%20Functions%20_scopus.pdf application/pdf en http://irep.iium.edu.my/65037/13/65037_Moment%20properties%20and%20quadratic%20estimating%20functions_WoS.pdf Mohamad, Nurul Najihah and Mohamed, Ibrahim and Haur, Ng Kok (2018) Moment properties and quadratic estimating functions for integer-valued time series models. Pakistan Journal of Statistics and Operation Research, 14 (1). pp. 157-175. ISSN 1816-2711 E-ISSN 2220-5810 http://www.pjsor.com/index.php/pjsor/article/view/1750/634 10.18187/pjsor.v14i1.1750 |
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Q Science (General) QA Mathematics Mohamad, Nurul Najihah Mohamed, Ibrahim Haur, Ng Kok Moment properties and quadratic estimating functions for integer-valued time series models |
description |
Recently, there has been a growing interest in integer-valued time series models. In this paper, using a
martingale difference, we prove a general theorem on the moment properties of a class of integer-valued
time series models. This theorem not only contains results in the recent literature as special cases but also
has the advantage of a simpler proof. In addition, we derive the closed form expressions for the kurtosis
and skewness of the models. The results are very useful in understanding the behaviour of the processes
involved and in estimating the parameters of the models using quadratic estimating functions (QEF).
Specifically, we derive the optimal function for the integer-valued GARCH (p, q) known as INGARCH (p,
q) model. Simulation study is carried out to compare the performance of QEF estimates with corresponding
maximum likelihood (ML) and least squares (LS) estimates for the INGARCH (1,1) model with different
sets of parameters. Results show that the QEF estimates produce smaller standard errors than the ML and
LS estimates for small sample size and are comparable to the ML estimates for larger sample size. For
illustration, we fit the 108 monthly strike data to INGARCH (1, 1) models via QEF, ML and LS methods,
and show the applicability of QEF method in practice. |
format |
Article |
author |
Mohamad, Nurul Najihah Mohamed, Ibrahim Haur, Ng Kok |
author_facet |
Mohamad, Nurul Najihah Mohamed, Ibrahim Haur, Ng Kok |
author_sort |
Mohamad, Nurul Najihah |
title |
Moment properties and quadratic estimating functions for integer-valued time series models |
title_short |
Moment properties and quadratic estimating functions for integer-valued time series models |
title_full |
Moment properties and quadratic estimating functions for integer-valued time series models |
title_fullStr |
Moment properties and quadratic estimating functions for integer-valued time series models |
title_full_unstemmed |
Moment properties and quadratic estimating functions for integer-valued time series models |
title_sort |
moment properties and quadratic estimating functions for integer-valued time series models |
publisher |
College of Statistical and Actuarial Sciences, University of Punjab |
publishDate |
2018 |
url |
http://irep.iium.edu.my/65037/ http://irep.iium.edu.my/65037/ http://irep.iium.edu.my/65037/ http://irep.iium.edu.my/65037/1/65037_Moment%20Properties%20and%20Quadratic%20Estimating%20Functions%20_article.pdf http://irep.iium.edu.my/65037/2/65037_Moment%20Properties%20and%20Quadratic%20Estimating%20Functions%20_scopus.pdf http://irep.iium.edu.my/65037/13/65037_Moment%20properties%20and%20quadratic%20estimating%20functions_WoS.pdf |
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2023-09-18T21:32:17Z |
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2023-09-18T21:32:17Z |
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1777412590416166912 |