--- Marco Buur wrote:
> I would like to do linear extrapolation for Y for
> 2008 and 2009 with
>
> ipolate Y X, gen(E) epolate
>
> But I got odd results for 2008 and 2009!! It is
> going rapidly down specially 2009.
Notice that -ipolate- only looks at the two closest
observations when extrapolating, and your last two
observed observations indicate a downward trend. For
more see the manual entry for -ipolate-. Maybe you
are looking for the last solution in the example
below?
*-------------- begin example ------------
clear
input X long Y
2001 546794340
2002 593576317
2003 524389625
2004 592850956
2005 691340900
2006 1149327295
2007 895638411
2008 .
2009 .
end
ipolate Y X, gen(E) epolate
reg Y X
predict yhat
list
*--------------- end example ---------------
( For more on how to use examples I sent to statalist see:
http://www.maartenbuis.nl/stata/exampleFAQ.html )
Hope this helps,
Maarten
--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://www.maartenbuis.nl
--------------------------
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