Hall, Anthony D.; Skalin, Joakim; Teräsvirta, Timo - Economics Institute for Research (SIR), … - 1998
A smooth transition autoregressive model is estimated for the Southern Oscillation Index, an index commonly used as a measure of El Niño events. Using standard measures there is no indication of nonstationarity in the index. A logistic smooth transition autoregressive model describes the most...