Re: st: simple plot of fitted probabilities

[Maarten buis <maartenbuis@yahoo.co.uk>]

--- On Tue, 4/1/11, Lloyd Dumont wrote:
> Say you estimate a very simple probit model…
> 
> Probit Y X1 X2 X3 X4
> 
> The ultimate goal is a plot of fitted values
> (probabilities) in which predicted probability is shown as a
> function of X1 and all the other independent variables are
> held at their means.
> 
> Let’s first say X1 is just a typical continuous variable,
> say taking on ANY value [0,100] ?
> 
> Would it make a difference if X1 were a categorical rather
> than continuous, say taking on only 1,2,3, or 4?

There are many solutions possible, but typically I tend to use
-adjust- for this type of problem, like this:

*----------- begin example ---------------
sysuse auto, clear
probit foreign price rep78 mpg
preserve
adjust rep78 mpg, pr by(price) ci replace
twoway rarea lb ub price, sort || ///
       line pr price, sort legend(off)
restore	  
*------------- end example ---------------
(For more on examples I sent to the Statalist see: 
http://www.maartenbuis.nl/example_faq )

This way you automatically deal correctly with continuous
and categorical variables.

Hope this helps,
Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://www.maartenbuis.nl
--------------------------


      

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