Re: st: Generation of Variables with reference to values in the same column

[Christopher Baum <kit.baum@bc.edu>]

<>
On Sep 14, 2012, at 7:33 AM, Arnold wrote:

> Is there an easy way to generate a variable that measures the change  
> in a given column?  Specifically I want to create a variable that is  
> equal to:
> 
>  log(CPIt) - log(CPIt-1)
> 
> I tried using the following code:
> 
> generate log(CPI[2])-log(CPI[1])
> 
> But that simply filled the column with the results of the function  
> using the values of CPI in rows 1 & 2.  Short of doing that manually  
> for each row, is there a way to write something like:
> 
> generate log(CPI[X]) - log(CPI[X-1])
> 
> That just goes down the column and calculates for each new row?  Or  
> should I just export into Excel?

(I presume that you have tsset the data)
g lcpi = log(CPI)
g inflation = D.lcpi

Kit

PS> What is "Excel"?

Kit Baum   |   Boston College Economics & DIW Berlin   |   http://ideas.repec.org/e/pba1.html
                             An Introduction to Stata Programming  |   http://www.stata-press.com/books/isp.html
  An Introduction to Modern Econometrics Using Stata  |   http://www.stata-press.com/books/imeus.html


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