st: -mfx- after poisson

[Scott Cunningham <scunning@gmail.com>]

I have a balanced panel of 3 years with approximately 800 individuals  
in each year (thus 2400 observations more or less).  I ran a poisson  
MLE with clustered and robust standard error correction.  There were  
several variables as regressors, but three worth mentioning (because  
I think they are causing the problem) are

i.year
i.fip
i.year*i.fip

That is, I am controlling for year, state and state-year fixed  
effects, and am using xi:poisson.

The ML converges without any problems.  But when I use the -mfx- post- 
estimation command to get the marginal effects, it takes a long  
time.  In fact, it's been going for over a day and still has not  
produced anything.  So my question is - do I need to just be  
patient?  Why would this take so long?  I have approximately 200 of  
these fixed effects, so possibly it has something to do with this,  
and I just need to be patient?  Or, is this sympotmatic of something  
else?  And why might -mfx- break down like that at all? Should I  
consider -prchange- instead?  And if I do use -prchange-, will it  
easily adapt into -estout- so that I can save the estimates and  
produce tables?

thanks,


scott
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