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From | David Hoaglin <dchoaglin@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Interpretation of interaction term in log linear (non linear) model |
Date | Wed, 12 Jun 2013 21:21:16 -0400 |
Dear Suryadipta, A key idea underlying Bill Gould's blog post is that -poisson- enables you to use quasi-likelihood. That command does not require that the data follow a Poisson distribution. Please read carefully the part of the blog post that discusses zero values. I doubt that simply fitting your model by using -poisson- will adequately handle your "many zeros." Regards, David Hoaglin On Wed, Jun 12, 2013 at 12:06 PM, Suryadipta Roy <sroy2138@gmail.com> wrote: > Dear David, > I have used both log linear model (that apply only to country pairs > with nonzero bilateral imports) as well as fixed effects Poisson to > include the zero observations (based on some wonderful suggestions > from Bill Gould in Statablog here > http://blog.stata.com/2011/08/22/use-poisson-rather-than-regress-tell-a-friend/). > Earlier, Dimitriy had suggested an intuitive interpretation of the > coefficient terms in terms of semi-elasticity, and I can probably > persist with that interpretation for Poisson regression. > > Best regards, > Suryadipta. * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/