This paper introduces the class of volatility modulated Lévy-driven Volterra (VMLV) processes and their important subclass of Lévy semistationary (LSS) processes as a new framework for modelling energy spot prices. The main modelling idea consists of four principles: First, deseasonalised spot...

This paper aims to describe bias estimates when non-stationary variance is not detected. We first present a theoretical multivariate GARCH model with structural changes in variance. Then we describe the non-stationary variance and Volatility Causality in the case of the US and the three...

Using positive semidefinite supOU (superposition of Ornstein-Uhlenbeck type) processes to describe the volatility, we introduce a multivariate stochastic volatility model for financial data which is capable of modelling long range dependence effects. The finiteness of moments and the second...

Using the Tsay (1988) outlier identification methodology on daily log-returns of 16 commodity spot price series and 25 commodity index series, this study assesses the impact significant and unexpected news announcements had on volatility between January 1, 1997 and December 31, 2007. Results...