We investigate the impact of the European Central Bank's monetary policy an- nouncements on the level and volatility of the EUR-US Dollar exchange rate em- ploying an AR-FIGARCH specification. Using high-frequency data we estimate the individual and complementary effects of the release of the...

This paper considers a formulation of the extended constant or time-varying conditional correlation GARCH model which allows for volatility feedback of either sign, i.e., positive or negative. In the previous literature, negative volatility spillovers were ruled out by the assumption that all...

In this article we derive conditions which ensure the non-negativity of the conditional variance in the Hyperbolic GARCH(p; d; q) (HYGARCH) model of Davidson (2004). The conditions are necessary and suffcient for p < 2 and suffcient for p > 2 and emerge as natural extensions of the inequality constraints derived in...</2>