Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: st: emptycells(reweight)
From
"Valle, Giuseppina" <[email protected]>
To
"[email protected]" <[email protected]>
Subject
RE: st: emptycells(reweight)
Date
Thu, 23 Jan 2014 22:59:36 +0000
Thanks. I just wanted to double check there wasn't anything further.
-Pina
Sent using OWA for iPhone
________________________________________
From: [email protected] <[email protected]> on behalf of Steve Samuels <[email protected]>
Sent: Thursday, January 23, 2014 4:46:43 PM
To: [email protected]
Subject: Re: st: emptycells(reweight)
What you are seeing is expected behavior. If you read the -help- you will see that
-set emptycells drop- affects only whether empty cells appear in the output.
Steve
[email protected]
On Jan 23, 2014, at 1:33 PM, "Valle, Giuseppina" <[email protected]> wrote:
Thank you so much for your reply, Steve.
I also tried the command "set emptycells drop" before running my regression, and all of the coefficients for the remaining interaction terms, as well as the margins, are the same whether or not I include this statement.
If anyone has insight on that, it would be greatly appreciated.
Thanks,
Pina
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Steve Samuels
Sent: Monday, January 20, 2014 11:54 AM
To: [email protected]
Subject: Re: st: emptycells(reweight)
Giuseppina
The output is correct. You are apparently under the impression that the
-emptycells(reweight)- option will modify cell means. It doesn't; it only changes the weight given to the existing (non-missing) means.
According to the manual:
"emptycells(reweight) specifies that the effects of the observed cells be increased to accommodate any missing cells. This makes the margin estimable but changes its interpretation."
Nothing is said about changing anything in the missing cells.
The purpose of -emptycells(reweight)- is to make it possible to estimate lower-order margins in the presence of missing cells.
To see what is going on, try the following with and without the
-asbalanced- and -emptycells(reweight)- options.
margins timing
margins sexpart
Steve
[email protected]
On Jan 16, 2014, at 11:48 AM, Valle, Giuseppina wrote:
Hello,
I am trying to estimate margins for an interaction term (3 x 5), but I have an empty cell. In order to reconcile this, have tried to use the emptycells(reweight) option. However, I am still getting the following:
This is from the regression:
timing#sexpart |
1 1 | 0 (empty)
1 3 | -.8425747 1.120406 -0.75 0.453 -3.059825 1.374676
1 4 | -.3740791 1.035008 -0.36 0.718 -2.42233 1.674172
1 5 | -1.175772 .8898283 -1.32 0.189 -2.936716 .5851718
3 1 | -.6043734 .5221451 -1.16 0.249 -1.637683 .4289364
3 3 | -.203632 .3666424 -0.56 0.580 -.9292065 .5219424
3 4 | 1.250838 .5659914 2.21 0.029 .130758 2.370919
3 5 | -.6449708 .4828192 -1.34 0.184 -1.600456 .3105142
This is from the margins using the following syntax:
margins timing#sexpart, subpop(if gender==1) asbalanced emptycells(reweight)
Predictive margins Number of obs = 4886
Subpop. no. obs = 2082
Model VCE : Linearized
Expression : Pr(drinkw4), predict()
Empty cells : reweight
at : timing (asbalanced)
race (asbalanced)
famstw1 (asbalanced)
respeduc (asbalanced)
respinc (asbalanced)
sexpart (asbalanced)
--------------------------------------------------------------------------------
| Delta-method
| Margin Std. Err. z P>|z| [95% Conf. Interval]
---------------+--------------------------------------------------------
---------------+--------
timing#sexpart |
1 1 | . (not estimable)
1 2 | .2007178 .1292118 1.55 0.120 -.0525326 .4539682
1 3 | .1723023 .0888076 1.94 0.052 -.0017573 .3463619
1 4 | .2542255 .1413226 1.80 0.072 -.0227617 .5312126
1 5 | .2081755 .0813572 2.56 0.011 .0487182 .3676327
2 1 | .0763753 .0326297 2.34 0.019 .0124223 .1403284
2 2 | .1468328 .0297079 4.94 0.000 .0886064 .2050593
2 3 | .2425471 .0450327 5.39 0.000 .1542846 .3308096
2 4 | .2508539 .0537633 4.67 0.000 .1454798 .356228
2 5 | .3561694 .0553567 6.43 0.000 .2476723 .4646665
3 1 | .0494258 .0169824 2.91 0.004 .0161408 .0827107
3 2 | .1634568 .0325718 5.02 0.000 .0996172 .2272964
3 3 | .2301516 .0512481 4.49 0.000 .1297071 .3305962
3 4 | .552356 .1150508 4.80 0.000 .3268606 .7778514
3 5 | .2537699 .0858682 2.96 0.003 .0854713 .4220684
--------------------------------------------------------------------------------
Is there something I am doing incorrectly? I have read much of what is the stata manual regarding this command, but it seems to still not be working. Any advice would be greatly appreciated!
Thanks,
Pina
*
* 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/
*
* 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/