Re: st: RE: -prgen- with a quadratic function

 From Mariano Sana To statalist@hsphsun2.harvard.edu Subject Re: st: RE: -prgen- with a quadratic function Date Wed, 16 Mar 2005 09:03:14 -0600

```

Thanks everybody! (Nick C., Nick W., Scott)

It looks like I can play with various ways to get this done!

Mariano

From:owner-statalist@hsphsun2.harvard.edu on 03/15/2005 09:20 PM EST

Sent by: owner-statalist@hsphsun2.harvard.edu

To:   statalist@hsphsun2.harvard.edu
cc:   (bcc: Mariano Sana/msana/LSU)

Subject:    Re: st: RE: -prgen- with a quadratic function

Also, my -oprobpr- can do this; it is available from SSC.

--Nick Winter

At 10:03 PM 3/15/2005 +0000, you wrote:
>I don't think Scott Long is a member of Statalist.
>
>followed by an appropriate graph.
>
>Nick
>n.j.cox@durham.ac.uk
>
>Mariano Sana
>
> > Hi Statalisters.  Someone experienced with ?prgen- might be
> > able to answer this.
> >
> > I ran a logit model that has, among its predictor variables,
> > AGE and AGESQ.
> > The coefficient for AGE is positive and the coefficient for AGESQ is
> > negative.  The turning point is at age 79 or so.  I?ve been trying to
> > generate a graph that shows how predicted probabilities vary
> > by age for a few groups in my analysis.  I used the -prgen- command
from
> >
> > The graph that I get doesn't make sense. The probability
> > increases nonstop
> > and becomes asymptotic to 1 at age 90 or so.
> >
> > I realize that the problem is that -prgen- cannot vary the
> > value of AGESQ
> > as the value of AGE varies.  The default for AGESQ is the
> > mean of AGESQ,
> > unless I specify another value.  Obviously, I need AGESQ to
> > be the square of AGE as AGE varies.
> >
> > By now I think I have no other solution than running
> > -prvalue- (also from
> > the Spostado package) multiple times to get the probabilities
> > I need for
> > the graph. Or is there any other way? Is this a question for
> > Scott Long?
>
>*
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--------------------------------------------------------
Nicholas Winter                           607.255.8819 t
Assistant Professor                       607.255.4530 f
Department of Government              nw53@cornell.edu e
308 White Hall            falcon.arts.cornell.edu/nw53 w
Cornell University
Ithaca, NY 14853-4601

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```