Testing for double threshold autoregressive conditional heteroscedastic model

The testing problem for the hypothesis of linearity against the double threshold autoregressive conditional heteroscedastic model is addressed. The, problem is nonstandard as the threshold parameter is a nuisance parameter which is absent under the null hypothesis. We will show that the asymptotic null distribution of the Lagrange-multiplier test statistic is a functional of a zero-mean Gaussian process. In some cases, we give the upper percentage points of the test statistic. The performance of the test statistic is illustrated by extensive simulation experiments and an example. Copyright © 2000 Institute of Statistical Science, Academia Sinica.