Re: st: Pmatch2 and random

["Gauri Khanna" <gwkhanna@hotmail.com>]

Dear Steven,

Thank you for responding to my question. I will then continue with my work 
as is.

Have a nice weekend.

Sincerely,

Gauri



> From: Steven Samuels <ssamuels@albany.edu>
> Reply-To: statalist@hsphsun2.harvard.edu
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: Pmatch2 and random
> Date: Fri, 13 Apr 2007 07:51:10 -0400
>
> This is expected behavior.  The fact that you randomly sorted the  
> observations doesn't change the fact that some have the same  propensity 
> scores (often because the scores are based primarily on  categorical 
> variables so that there are many ties).
> On Apr 13, 2007, at 5:26 AM, Gauri Khanna wrote:
>
>
> > Dear Stata list,
> >
> > I am running the psmtach2 command to estimate propensity scores. I  use 
> > Stata 9.2 and psmatch2 is updated.
> >
> > While running this command, in my output I get a comment:
> >
> > "There are observations with identical propensity score values.
> > The sort order of the data could affect your results.
> > Make sure that the sort order is random before calling psmatch2"
> >
> > So I do the following
> > -gen random=uniform()
> > sort random-
> >
> > but still get the same message
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