Doctoral Dissertations
Keywords and Phrases
Asymmetry in volatility; GARCH-type models; Long- and short-term memory in volatility; Mixture memory; Smooth transition; Threshold model
Abstract
"The volatility of asset returns is usually time-varying, necessitating the introduction of models with a conditional heteroskedastic variance structure. In this dissertation, several existing formulations, motivated by the Generalized Autoregressive Conditional Heteroskedastic (GARCH) type models, are further generalized to accommodate more dynamic features of asset returns such as asymmetry, long memory, and structural breaks. First, we introduce a hybrid structure that combines short-memory asymmetric Glosten, Jagannathan, and Runkle (GJR) formulation and the long-memory fractionally integrated GARCH (FIGARCH) process for modeling financial volatility. This formulation not only can model volatility clusters and capture asymmetry but also considers the characteristic of long memory in the volatility. In the second paper, we extend the Hybrid GJR and FIGARCH process to allow for a graduate transition between two regimes by introducing a smooth transition function. Here, the model changes smoothly between the extremes of the asymmetric short and long memory components depending on a transition variable. The third paper proposes a regime-switching asymmetric long memory model, Multiple Regime Hyperbolic GARCH (MR-HYGARCH), where the regime of an asset return is determined by observing asymmetry between positive and negative returns in its past long-term and past short-term periods. Firstly, it introduces a customizable multiple regime switching mechanism, allowing for tailored modeling according to specific problem requirements. Secondly, it proposes a new specification featuring four regimes governed by a dynamic threshold, in contrast to existing threshold GARCH models that rely on a fixed threshold with only two regimes. Finally, a multiplicative component process (MF)2EGARCH that models the conditional variance as the product of a short-term volatility component, modeled as an exponential GARCH (EGARCH) process and a long-term component, is introduced. Overall, the proposed models demonstrate superior performance compared to their respective competing models in both in-sample estimation and out-of-sample forecasting capabilities"--Abstract, p. iv
Advisor(s)
Samaranayake, V. A.
Committee Member(s)
Gelles, Gregory M.
Olbricht, Gayla R.
Paige, Robert L.
Wen, Xuerong Meggie
Department(s)
Mathematics and Statistics
Degree Name
Ph. D. in Mathematics and Statistics
Publisher
Missouri University of Science and Technology
Publication Date
Summer 2023
Pagination
xiv, 179 pages
Note about bibliography
Includes_bibliographical_references_(pages 169-178)
Rights
© 2023 K. C. M. R. Anjana Bandara Yatawara, All Rights Reserved
Document Type
Dissertation - Open Access
File Type
text
Language
English
Thesis Number
T 12305
Electronic OCLC #
1427270276
Recommended Citation
Yatawara, K C M R Anjana Bandara, "Essays on Conditional Heteroscedastic Time Series Models with Asymmetry, Long memory, and Structural Changes" (2023). Doctoral Dissertations. 3272.
https://scholarsmine.mst.edu/doctoral_dissertations/3272