st: Using postfile to save single observations from a dataset

[Nick Baker <nb419@cam.ac.uk>]

Hi all,

I currently have a time series dataset where the variables are the returns 
of several hundred mutual funds:

	Date	retfund1	retfund2
1	2006m1	-12.38985	10.39785
2	2006m2	-8.219995	9.54027
3	2006m3	5.497518	-5.947091
4	2006m4	-0.9465399	-2.846269
5	2006m5	2.219898	-12.51931
6	2006m6	0.4326888	-2.443768

What I want to do is to get these data into a long form with information on 
lagged returns:

FundID	Date	ret(t-1)	ret(t-2)
1	2006m1	.	.
1	2006m2	-12.38985	.
1	2006m3	-8.219995	-12.38985
1	2006m4	5.497518	-8.219995
1	2006m5	-0.9465399	5.497518
1	2006m6	2.219898	-0.9465399
2	2006m1	.	.
2	2006m2	10.39785	.
2	2006m3	9.54027	10.39785
2	2006m4	-5.947091	9.54027
2	2006m5	-2.846269	-5.947091
2	2006m6	-12.51931	-2.846269


Currently, for each fund I am generating variables of lagged returns and am 
then attempting to save each observation to a seperate dataset using 
postfile within a forvalues loop over the date range. However the resulting 
postfile does not contain a single observation. Has anyone else had a 
similar problem? Is there a way to do this without attempting to loop over 
obsevations?

Many Thanks, 

Nicholas Baker



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