Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: RE: RE: about 'forvalues' loop


From   "Nick Cox" <n.j.cox@durham.ac.uk>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: RE: about 'forvalues' loop
Date   Tue, 8 Sep 2009 12:52:55 +0100

The last line would be better as 

by cy: replace kstck = 0.93 * L.kstck + L.gfc if _n > 1 

Nick 
n.j.cox@durham.ac.uk 

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
Sent: 08 September 2009 12:42
To: statalist@hsphsun2.harvard.edu
Subject: st: RE: about 'forvalues' loop

0. A problem that will bite
============================

The syntax `i-1' won't work. It would need to be `=`i' - 1' 

That is legal, but in your case it looks as if you have various other
problems that affect your code earlier. 

1. A problem that won't bite
============================

In 

bysort cy: gen kstck = 0

the -bysort- does no harm, but it does nothing. The result is 0,
regardless of -cy-. 

2. A general problem
====================

Reshaping to wide will on balance make your life _much_ more difficult
here. 

It looks as if a better approach would be something like 

gen kstck = 0 
tsset cy yr 
by cy: replace kstck = 0.93 * L.kstck + L.gfc 

Nick 
n.j.cox@durham.ac.uk 


Marwan Elkhoury

sorry again to bother you with some very stupid question but I'm  
getting stuck again on some simple matter that I believe is in the  
writing of scalar.

the story is that I have a panel data and I'ld like to generate a new  
variable called kstck (by country (cy)).

so I run this loop:

bysort cy: gen kstck = 0
reshape wide gdp gfc kstck, i(cy) j(yr)

* Calculate capital stock from 1990 to 2000 using the following  
formula (where gfc* is the investment in year *)

bysort cy: replace kstck1990 = gfc1990

forvalues i = 1991/2000 {
bysort cy: replace kstck`i' = .93*kstck`i-1' + gfc`i'
}

However, it is not giving me the required result of the recursive  
summation.  why ?

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   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