# Re: st: mfx

 From "Joao Ricardo F. Lima" To statalist@hsphsun2.harvard.edu Subject Re: st: mfx Date Fri, 18 Jul 2008 20:11:35 -0300

```Dear,

sorry the simple question. I am curious why I have to use "x" instead
mpg (mean) in the twoway graph (..._b[mpg]*x+_b...)? Or better, what
Stata understand when I type x in this command?

Thanks a lot,

Joao Ricardo

2008/7/18 Arne Risa Hole <arnehole@gmail.com>:
> Hi Chiara,
>
>
> sysuse auto
> probit foreign price mpg
> mfx
> sum price
> local mean_price = r(mean)
> #delimit ;
> twoway (function y = _b[mpg]*normden(_b[price]*`mean_price'+
> _b[mpg]*x+_b[_cons]), range(mpg)) ;
> #delimit cr
>
> This plots the marginal effect of the mpg variable over its range
> following a probit regression. The logic is the same with -biprobit-
> but the formula for the marginal effect will of course be a little
> more intricate in that case.
>
> Arne
>
> 2008/7/18 Chiara Mussida <cmussida@gmail.com>:
>> Dear All,nuous variab
>> is there a way to "plot" the mfx of a continuous variable (after a
>> biprobit) to infer its behaviour over the complete range of values and
>> not only for the mean of the independent variables (which is the
>> default)?
>>
>> Thanks
>>
>> --
>> Chiara Mussida
>> PhD candidate
>> Doctoral school of Economic Policy
>> Catholic University, piacenza (Italy)
>> *
>> *   For searches and help try:
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>> *   http://www.stata.com/support/statalist/faq
>> *   http://www.ats.ucla.edu/stat/stata/
>>
> *
> *   For searches and help try:
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> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>

--
-------------------------------
Joao Ricardo Lima
Professor
UFPB-CCA-DCFS
+553138923914
-------------------------------
*
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*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```

• Follow-Ups:
• Re: st: mfx
• From: "Arne Risa Hole" <arnehole@gmail.com>
• References:
• st: mfx
• From: "Chiara Mussida" <cmussida@gmail.com>
• Re: st: mfx
• From: "Arne Risa Hole" <arnehole@gmail.com>