In this research, a new class of time series models capturing dynamic seasonality is introduced. Unlike traditional seasonal models which focus mainly on the mean process, our approach can accommodate dynamic seasonality in the mean and variance processes. This feature allows us to perform...

This paper studies the statistical properties of a two-step conditional quantile estimator in nonlinear time series models with unspecified error distribution. The asymptotic distribution of the quasi-maximum likelihood estimators and the filtered empirical percentiles is derived. Three...

To capture mean and variance asymmetries and time-varying volatility in financial time series, we generalize the threshold stochastic volatility (THSV) model and incorporate a heavy-tailed error distribution. Unlike existing stochastic volatility models, this model simultaneously accounts for...