The overid routine has been extensively rewritten. It can be invoked after
ivreg or ivreg2, and now produces a variety of test statistics for
overidentifying restrictions (Sargan's statistic with and without
small-sample correction, Basmann's statistic, and pseudo-F forms of each).
The help file is much more informative, with references to the econometric
literature. overid now requires Stata version 7.0.
Available from SSC via ssc install overid [,replace].
