Re: st: Grouping income variables- RECODE COMMAND

[Nick Cox <njcoxstata@gmail.com>]

-lhincome- is still in your model, still missing sometimes, and
observations are still dropped from fitting whenever it is missing.

You need to replace -lhincome-.
Nick
njcoxstata@gmail.com


On 4 February 2014 12:48, Antonio Rodriguez Andres
<Antonio.Andres@emu.edu.tr> wrote:
> Dear Maarten
>
> Thank you very much for your feedback. What I did is the following
>
> http://www3.nd.edu/~rwilliam/stats2/l12.pdf
>
> *Create income midpoints
>
> recode hinctnt (1=900) (2=2700) (3=4800) (4=9000) (5=15000) (6=21000) (7=27000) (8= 33000) (9=48000) (10=75000) (11=105000) (12= 175200) , gen(hincome)
> replace hincome=. if hinctnt==77 | hinctnt==88 |  hinctnt==99
> gen lhincome=log(hincome)
>
> **dummy indicator for missing income values
>
> gen xhincome=hincome
> replace xhincome= 29304.99 if missing(hincome)
> gen md=0
> replace md=1 if xhincome! =hincome
>
> xtmixed dprt age age2 gender married separated divorced widowed eduyrs ichldhm md lhincome ihealth iuemp5yr iuemp12m rgdp06[pw=dweight] if md==0 || cntry: gender , mle
>
>
> But I still got the same message, the md indicator variable is dropped. How can İ estimate the model controlling for missing values in income?
>
> Antonio
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Maarten Buis
> Sent: Tuesday, February 04, 2014 2:26 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: Grouping income variables- RECODE COMMAND
>
> On Tue, Feb 4, 2014 at 12:29 PM, Antonio Rodriguez Andres wrote:
>
>> First of all, I recode the household income variable using mıd-points. The problem is defining a midpoint for the open ended top category. For that purpose, I follow Hout (2004).
>> *Create income midpoints
>> recode hinctnt (1=900) (2=2700) (3=4800) (4=9000) (5=15000) (6=21000)
>> (7=27000) (8= 33000) (9=48000) (10=75000) (11=105000) (12= 175200) ,
>> gen(hincome) replace hincome=. if hinctnt==77 | hinctnt==88 |
>> hinctnt==99  // I recode hinctnt= 77 & 88 & 99 (Don’t Know,  Refusal, No answer) as missing values gen lhincome=log(hincome) I also need to include in my regression a dummy variable for the mıssing values corresponding to income. I type in Stata.
>> gen missinc=0
>> replace missinc=1 if missing(hincome)
>>
>> When estimating the following model, the dummy variable for missing values for income is dropped but ıt has to be in my model. Is there anything wrong with the Stata code?
>
> Two comments:
>
> First, don't do this, this is not a good way of dealing with missing values. See e.g.
> <http://www.stata.com/statalist/archive/2007-12/msg00030.html>
>
> Second, mechanically what is going on that most estimation commands exclude all observations that include at least one missing value on any of the variables included in the model. If you exclude all observations for which lhincome is missing than  missinc will be a constant containing only 0, and will thus be excluded.
>
> Hope this helps,
> Maarten
>
> ---------------------------------
> 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:
> *   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:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/