Modelling economic high-frequency time series with STAR-STGARCH models

Abstract

In this paper we introduce the STAR-STGARCH model that can characterize nonlinear behaviour both in the conditional mean and the conditional variance. A modelling cycle for this family of models, consisting of specification, estimation, and evaluation stages is constructed. Misspecification tests for the estimated model are obtained using standard asymptotic distribution theory. We illustrate the actual modelling by applying the STAR-STGARCH model family to two series of daily observations, the Swedish OMX index and the exchange rate JPY-USD.Financial time series; model misspecification test; nonlinear time series; smooth transition autoregressive model; smooth transition GARCH; time series model specification.