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From | Eric N <eric.erictor@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: checking over dispersion in XTPOISSON |
Date | Fri, 6 Jan 2012 10:07:51 -0500 |
One of the problems with Poisson is that the variance is assumed to equal the mean which is a very restriction condition. You might wish to try the negative binomial that also is used to analyze count data and is less restrictive in this regard. --Eric On 1/5/12, Rajaram Subramanian Potty <rajara999@gmail.com> wrote: > Dear all, > > I would like to know how one should check for overdispersion in a > model fitted using "xtpoisson". If one noticed overdispersion how to > correct it or which is the alternative analysis. > > Thanks in advance. > > > RAJARAM > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/