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RE: st: Looping Enquiry
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
RE: st: Looping Enquiry
Date
Thu, 29 Sep 2011 15:21:06 +0100
This is normally a good idea, but in this case the variable concerned is often negative, which to me implies that other methods have greater appeal.
Nick
[email protected]
Valerie Orozco
The first idea that comes in my mind is to transform the problem.
If you think in a sum rather than in a product it will be easier to program it.
Indeed, since the logarithm of a product is the sum of the logarithms, you can use it to program you formula easier in Stata.
score transform to log generate a cumulative sum transform to exponential to have what you want
x1 lnx1 lnx1 x1
x2 lnx2 lnx1+lnx2 x1x2
x3 lnx3 lnx1+lnx2+lnx3 x1x2x3
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