Statalist


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

Re: st: missing p-value from t-test


From   Maarten buis <maartenbuis@yahoo.co.uk>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: missing p-value from t-test
Date   Fri, 23 May 2008 10:28:01 +0100 (BST)

--- Ngoc Anh Vo Thi <vtnanh@yahoo.com> wrote:
> I'm estimating the following model using OLS:
> lnROA=alpha + beta(1)*lnW(1) + beta(2)*lnW(2) + beta(3)*lnW(3) +
> gamma*D + epsilon.
> 
> Then I calculate an E statistic that equals the sum of beta(1),
> beta(2), and beta(3). I want to test whether E=0, using a t-test:
> ttest  E==0
<snip>
> I would like to know why all the p-values are missing here? Is it
> because E is a fixed value for all observations? If this is the case,
> how can I test this hypothesis, i.e. E=0?

*---------------- begin example ---------------
sysuse auto
reg mpg rep78 trunk turn
test rep78 + trunk + turn = 0
*----------------- end example ----------------
(For more on how to use examples I sent to the Statalist, see
http://home.fsw.vu.nl/m.buis/stata/exampleFAQ.html )

Hope this helps,
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/
-----------------------------------------


      __________________________________________________________
Sent from Yahoo! Mail.
A Smarter Email http://uk.docs.yahoo.com/nowyoucan.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/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index