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st: RE: -prgen- with a quadratic function
I don't think Scott Long is a member of Statalist.
No matter: your problem should yield to -adjust-
followed by an appropriate graph.
> 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 Spostado package.
> 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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