Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too … variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH … terms only. The empirical application on U.S. dollar exchange rates shows that our model indeed yields better volatility …

more important for higher rated bonds (AAA and AA).The stock return and the implied volatility of the stock price seem to …

consumption growth process. The hidden states di¤er both for the mean and the volatility. We show that the ambiguity …-averse investor downweights high-mean states in favor of low-mean ones. However, such distortion appears much stronger in low-volatility … regimes: high volatility attenuates the distortion due to ambiguity concerns. It follows that (i) ambiguity aversion always …

An exact discretization of continuous time stochastic volatility processes observed at irregularly spaced times is used …