Inferential Procedures for the Generalized Gamma Distribution

Abstract

The maximum likelihood estimators of the parameters of the generalized gamma distribution are shown to have the property that are distributed independently of a and b. Similar properties are also obtained for some Weibull-type statistics. These results are applied in particular to the problem of discriminating between the Weibull model and the generalized gamma model, and several test statistics are considered. In general, the Weibull model is quite flexible and, unless the sample size is quite large, is perhaps a preferable assumption because of the computational complexity and other difficulties encountered with the generalized gamma distribution.