Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: Autocorrelation in Poisson regression


From   "Stas Kolenikov" <skolenik@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Autocorrelation in Poisson regression
Date   Wed, 6 Aug 2008 17:06:48 -0500

On Wed, Aug 6, 2008 at 4:00 PM, Antonio Silva <asilva100@live.com> wrote:
> In response, I have some comments and a few more questions. First, for Kieran, let me clarify: My dependent variable is "# of groups founded." What this means is that for each year of the study (there are 40 years) there is a number, which represents the number of new organizations that come into existence in that year. So, for example, in 1965, 3 new groups were formed, in 1966, 2 new groups were formed, and in 1967 0 new groups were formed. So I have a number for each year in the period under study. Does that make sense?  I have tested for overdispersion and this is not a problem.

Oh, then your potential autocorrelation can go either way. You can
argue that cities (countries? areas?) that have more groups formed
might have attractive group-building climate, so you would expect more
groups to be formed there. On the other hand, you can also argue that
there might be saturation in that no area "needs" more that 10 groups
say. So the "autocorrelation" would rather be negative. That's a funny
problem though.

I think I posted proto-syntax for residual prediction -- you would
need to use -glm- command rather than -poisson-.

-- 
Stas Kolenikov, also found at http://stas.kolenikov.name
Small print: I use this email account for mailing lists only.
*
*   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/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index