Re: st: Calculating predicted probabilities at a given value of one of the independent variables

["Vitorino, Maria Ana" <vitorino@wharton.upenn.edu>]

Thanks!! But the results should be the same as in your previous suggestion, right? Or am I missing something?

Ana


On Oct 26, 2011, at 10:53 PM, "Richard Williams" <richardwilliams.ndu@gmail.com> wrote:

> At 06:06 PM 10/26/2011, Maria Ana Vitorino wrote:
>> Dear Statalist users,
>> 
>> I would like to calculate some predicted probabilities after fitting a
>> multinomial logit model (asclogit). But, the twist is that I would
>> like to calculate these fitted values for a given level of one of the
>> independent variables. Namely, I would like to set one of the Xs to
>> zero when computing the predicted probability (but not in the
>> estimation).
>> What would be the best way of going about this? Would it make sense to
>> do it in 2 steps? In the first step use  "predict xb" and in the
>> second step remove the component of xb that I'm not interested and
>> calculate the probability using "gen" and the logit formula?
>> Or is there a better way?
> 
> I am going to slightly tweak my earlier advice. Assuming you only want in-sample predictions,
> 
> webuse sysdsn1, clear
> clonevar xmale = male
> mlogit insure age i.xmale nonwhite i.site
> predict p1 p2 p3 if e(sample)
> replace xmale = 0 if !missing(xmale)
> predict pp1 pp2 pp3 if e(sample)
> 
> 
> -------------------------------------------
> Richard Williams, Notre Dame Dept of Sociology
> OFFICE: (574)631-6668, (574)631-6463
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> EMAIL:  Richard.A.Williams.5@ND.Edu
> WWW:    http://www.nd.edu/~rwilliam
> 
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