robust estimation of both long-run and short-run volatilities. Our estimation is semiparametric since the long-run volatility … propose different robust estimation methods for nonstationary and strictly stationary GARCH parameters with nonparametric long … run volatility function. Our estimation is based on a two-step LAD procedure. We establish the relevant asymptotic theory …

dealing with more than one lag. When the mean has an additive structure, however, better estimation methods are available … estimation of the conditional mean, it is equally if not more important to measure the future risk of the series along with the … interpretation of each lagged value's influence on such a function. In this paper we consider the joint estimation of both the …