The empirically most relevant stylized facts when it comes to modeling time varying financial volatility are the asymmetric response to return shocks and the long memory property. Up till now, these have largely been modeled in isolation though. To more flexibly capture asymmetry also with...

We introduce the notions of short and long term asymmetric effects in volatilities. With short term asymmetry we mean the conventional one, i.e. the asymmetric response of current volatility to the most recent return shocks. However, there may be asymmetries in the way the effect of past return...

The paper suggests a nonlinear and multivariate time series model framework that enables the study of simultaneity in returns and in volatilities, as well as asymmetric effects arising from shocks and an outside stock exchange. Using daily data 2000-2006 for the Baltic state stock exchanges and...