Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

RE: st: missing z-values when using dprobit


From   "Ohinata, Asako" <[email protected]>
To   <[email protected]>
Subject   RE: st: missing z-values when using dprobit
Date   Mon, 26 Nov 2007 22:43:35 -0000

Dear Maarten

Thank you for your reply. Yes, it is a reference category. After sending
the e-mail, I realised that standard error is missing from the same
variable when I run probit instead of dprobit. I think the main problem
is that the model contains too many dummy variables as when I drop some
of them, all the standard errors are estimated. I am wondering, however,
if there are any solutions other than dropping variables.

Best Wishes,
Asako



-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Maarten buis
Sent: 26 November 2007 22:23
To: [email protected]
Subject: Re: st: missing z-values when using dprobit 

--- "Ohinata, Asako" <[email protected]> wrote:

> Dear All
> 
> I am currently running dprobit with many dummy variables as well as 
> some continuous variables (i.e. age etc). When I run the regression, 
> some of the z-values are missing although standard errors are 
> estimated.
> 
>    Y	   |      dF/dx   Std. Err.      z  
> kid3plus*|          1   2.86e-71        .  <snip>

> Could you please let me know when STATA compute standard errors but 
> not z-values?

The standard error is in the example is very very small (0.0000000000000
00000000000000000000000000000000000000000000000000000000286), i.e. de
facto zero. So I am not surprized the z-score is missing. Is kid3plus
the reference category?

-- Maarten

-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands

visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434

+31 20 5986715

http://home.fsw.vu.nl/m.buis/
-----------------------------------------


      ___________________________________________________________
Want ideas for reducing your carbon footprint? Visit Yahoo! For Good
http://uk.promotions.yahoo.com/forgood/environment.html
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index