Statalist


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

Re: st: Weighted Least Squares


From   Maarten buis <maartenbuis@yahoo.co.uk>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Weighted Least Squares
Date   Tue, 15 Apr 2008 15:57:43 +0100 (BST)

I read your question as follows: 
- you have two (or more) variables: x1 = % in zone1, and x2 = % in
  zone 2, which must add up to 100%
- x1 and x2 are explanatory variables
- you want these variables to have only one effect instead two (or
  more) because you see them as one variable.

Is that correct?

-- Maarten


--- Tam Phan <tamdphan@gmail.com> wrote:

> Hello Stata Users:
> 
> I have a quick question on weighted Least squares:  Below is the
> following econometric equation:
> 
> Q1+Q2 = alpha + [  (Q1/(Q1+Q2))*X1 + (Q2/(Q1+Q2))*X2 ]b + e
> 
> Where X1 and X2 are the same explanatory variables, however with
> different numerical values.  For example, X1 would be the % in one
> zone, and X2 is the percent in another zone.
> 
> Is there anything wrong w/ this logic?
> 
> How about this econometric model:
> 
> y1=alpha1+beta1(P)+e
> y2= alpha2 +beta2(P)+v
> 
> To obtain the aggregate effect one would sum:
> 
> y1+y2=(alpha1+alpha2) +(beta1+beta2)P+(e+v)
> 
> Is there anything wrong with the above logic?
> 
> Tam
> 
> Tam
> *
> *   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/
> 


-----------------------------------------
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/
-----------------------------------------


      ___________________________________________________________ 
Yahoo! For Good helps you make a difference  

http://uk.promotions.yahoo.com/forgood/
*
*   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