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Re: st: Marginsplot after Poisson regression and negative predicted values
From
James Bernard <[email protected]>
To
[email protected]
Subject
Re: st: Marginsplot after Poisson regression and negative predicted values
Date
Wed, 8 Jan 2014 21:47:58 +0800
No, I mean that the Y variable that is a count variable on the y axis
is negative, while my dependent variable is count variable
On Wed, Jan 8, 2014 at 5:37 PM, Maarten Buis <[email protected]> wrote:
> I suspect that you mean the confidence interval around the predicted
> values. It is a known issue with the delta method that is used by
> -margins- for computing the confidence interval. Generally I would not
> worry too much about it, as these bounds are failry approximate
> anyhow, but if you do you can predict the linear predictor with its
> confidence intervals and transform those to the expected count metric
> as in <http://www.stata.com/support/faqs/statistics/delta-rule/index.html>.
>
> Hope this helps,
> Maarten
>
>
> On Wed, Jan 8, 2014 at 9:51 AM, James Bernard <[email protected]> wrote:
>> Hi all,
>>
>> I have ran a Poisson model. Then tried to run -margins and
>> -marginsplot for one of the variables.
>>
>> The shape of the graph makes sense. But, the range of predicted values
>> of the dependent variable (which is a count variable, obviously)
>> ranges from 1 at its maximum and -6 at its minimum. Is this usual? Am
>> I doing something wrong?
>>
>> Thanks,
>> James
>> *
>> * For searches and help try:
>> * http://www.stata.com/help.cgi?search
>> * http://www.stata.com/support/faqs/resources/statalist-faq/
>> * http://www.ats.ucla.edu/stat/stata/
>
>
>
> --
> ---------------------------------
> Maarten L. Buis
> WZB
> Reichpietschufer 50
> 10785 Berlin
> Germany
>
> http://www.maartenbuis.nl
> ---------------------------------
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/faqs/resources/statalist-faq/
> * http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
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* http://www.stata.com/support/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/