Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: Constraint, Poisson, & pseudo R^2


From   Rkaminski@aol.com
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Constraint, Poisson, & pseudo R^2
Date   Tue, 19 Oct 2004 15:59:49 EDT

Dave - thanks for your reply.  I'm not  using Scott's add on for the model 
estimation. Interestingly, Stata version 7  provides the pseudo-R^2 value when 
using the constraint, but version 8 does  not.  This makes me think Stata 
intentionally eliminated it from the output  in the latest incarnation. Hopefully 
someone will know the reason why. Maybe it  is not appropriate to report the 
R^2 value under these conditions?

Bob  Kaminski
Dept. of Criminology & Criminal Justice
University of South  Carolina

In a message dated 10/19/2004 1:50:37 PM Eastern Standard Time,  
jacobs.184@sociology.osu.edu writes:
That's almost certainly because Long and  Freeze use their add on program 
that calculates psuedo R squares.  I  can't remember the name of the add on 
program, but it is listed repeatedly  in the Long and Freeze book.

Dave Jacobs
Ohio State

At 08:00 AM  10/19/2004 -0400, you wrote:
>In the Long & Freeze book published  by  Stata, the authors estimate a 
Poisson
>regression model using the  constraint  command to control for unequal
>exposure. It produces the  same coefficients as  when using exposure or 
>offset, but
>the  pseudo-R^2 value is substantially larger  when using the constraint  
>option
>(p. 265). However, when I use the constraint  option,  Stata does not 
>produce a
>pseudo-R^2 value. Does anyone know  whether  there has been a change made to
>the program by  Stata?
>
>Thanks in  advance.
>
>Bob  Kaminski
>  

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   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