Stationariy time series
I have a time series (Occ (%ocupation) vs. time stamp cfr. Time series model in annex) where the autocorrelation function shows a slow decay indicating non-stationarity, however the ADF test all are negative indicating a statationary Occ time series. Which criterion is right? I get extremely good resuts with ARMA as well as ARIMA (diffeferenced) models. Can I assess a non differenced (4,2) ARMA mo...