Over the last decades the tourism sector has played an increasingly important role in the socio-economic development of Portugal. We analyze data from the last fifty years from Portugal, comparing non-pandemic forecasts derived with ARIMA time series models for the triennium 2020-2022, that is,...

The asymmetric moving average model (asMA) is extended to allow forasymmetric quadratic conditional heteroskedasticity (asQGARCH). Theasymmetric parametrization of the conditional variance encompassesthe quadratic GARCH model of Sentana (1995). We introduce a framework fortesting asymmetries in...