Re: st: Margins error

[Issa Kohler-Hausmann <ikh210@nyu.edu>]

Thanks Amy, I am suddenly having luck with the following syntax but I am now trying to figure out conceptually what the right one would be to use:

margins r.arrestnum_cat@p_misdcon_cat, at(arr_re_combi=2 male =1 p_felcon=0 MisdArr=1) 

margins arrestnum_cat, at(p_misdcon_cat=(0 1)) at(arr_re_combi=2 male =1 p_felcon=0 MisdArr=1) 

Are you having any luck? I guess I am still confused about what the different forms mean. 

Thanks much,
 - issa


On Jul 1, 2012, at 12:16 PM, Amy Hsin wrote:

> You may want to read the thread "generating predicted values for
> growth models" that was posted yesterday.  I had similar problems with
> the margins command using xi.
> 
> Maarten and William's suggest was to drop the xi (see the response for
> details). That worked to a degree.
> 
> However, I am still having problems with the margins command to
> generate predictions and am hoping to receive some help.
> 
> Amy
> 
> On Sun, Jul 1, 2012 at 5:39 PM, Issa Kohler-Hausmann <ikh210@nyu.edu> wrote:
>> Hello -
>> 
>> I am sorry if this is a dumb question but I have having trouble with the "margins" command after running a logistic regression and I cannot figure out what I am misunderstanding.
>> 
>> I am trying to graph the effect of the number of misdemeanor convictions (p_misdcon_cat) on the likelihood of conviction to a misdemeanor crime (outcome --> convict_Misd). The problem (it seems to me) is that STATA does not recognize the variables for purposes of the margins command that were generated using xi. logit and I don't know any other way of doing this. It also seems from all of the examples online that this should work.
>> 
>> I ran the following logic model:
>> 
>> . xi: logit convict_Misd i.race_eth_cat male p_felcon i.p_misdcon_cat arrestnum_cat MisdArr, cluster(my_case_id)
>> 
>> I then get the following errors when I try the margins command evaluated at specified levels of my covariates.
>> 
>> . margins, dydx(p_misdcon_cat) at (_Irace_eth__2=1 male=1 p_felcon=0 arrestnum_cat=4 MisdArr=1)
>> 'p_misdcon_cat' not found in list of covariates
>> r(322);
>> 
>> .
>> . margins p_misdcon_cat, at (_Irace_eth__2=1 male=1 p_felcon=0 arrestnum_cat=4 MisdArr=1)
>> 'p_misdcon_cat' not found in list of covariates
>> r(322);
>> 
>> Any help would be greatly appreciated!
>> 
>> Thank you
>> 
>> 
>> 
>> *
>> *   For searches and help try:
>> *   http://www.stata.com/help.cgi?search
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>> *   http://www.ats.ucla.edu/stat/stata/
> 
> 
> 
> -- 
> Amy Hsin
> Assistant Professor of Sociology
> Queens College, City University of New York
> http://qcpages.qc.cuny.edu/~ahsin
> 
> *
> *   For searches and help try:
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> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/


*
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