We consider the behavior of model selection criteria in AR models wher
e the error terms are not normal by varying skewness and kurtosis. The
probability of estimating the true lag order for varying degrees of f
reedom (k) is the interest. For both small and large samples skewness
does not effect the performance of criteria under consideration. On th
e other hand, kurtosis does effect some of the criteria considerably.
In large samples and for large values of k the usual asymptotic theory
results for normal models are confirmed. Moreover, we showed that for
small sample sizes performance of some newly introduced criteria whic
h were not considered in Monte Carlo studies before are better. (C) 19
98 Elsevier Science S.A.