"Everything should be made as simple as possible, but not simpler." - Albert Einstein

Seminar Announcement

Statistical Modeling with COGARCH(p,q) Processes

Erdenebaatar Chadraa, Ph.D. Candidate, Department of Statistics, Colorado State University

Friday, August 28, 2009

10:00 a.m., Weber 223

ABSTRACT

In this dissertation, a family of continuous time GARCH processes, generalizing the COGARCH(1,1) process of Klüppelberg, et. al. (2004), is introduced and studied. The resulting COGARCH(p,q) processes, qp ≥ 1, exhibit many of the characteristic
features of observed financial time series, while their corresponding volatility and squared increment processes display a broader range of autocorrelation structures than those of the COGARCH(1,1) process. We establish sufficient conditions for the existence of a strictly stationary non-negative solution of the equations for the volatility process and, under conditions which ensure the finiteness of the required moments, determine
the autocorrelation functions of both the volatility and squared increment processes. The volatility process is found to have the autocorrelation function of a continuous-time ARMA process while the squared increment process has the autocorrelation function
of an ARMA process.

To estimate the parameters of the COGARCH(2,2) processes, the least-squares method is used. We give conditions under which the volatility and the squared increment processes are strongly mixing, from which it follows that the least-squares estimators are strongly
consistent and asymptotically normal. Finally, the model is fitted to a high frequency dataset.

Advisory Committee:
Dr. Peter Brockwell, Advisor
Dr. Haonan Wang, Committee Member

Dr. Chihoon Lee, Committee Member
Dr. Mahmood Azimi-Sadjadi, Electrical & Computer Engineering, Outside Member