Dear Statalist members,
I am merging two datasets, KP.dta and PS.dta, which were sorted by
the variable <id>. They contain the subjects who from two different
exposure groups.
Values for <id> are unique to each dataset, so that <id> occurs only
once in each dataset, and are not duplicated across datasets.
Before the merge,
In dataset KP, one variable <smoker> has values yes or no: 1/0.
In dataset PS, <smoker> is missing.
However, after the merge, PS now has values for <smoker>.
I merged using this command:
use "A.dta", clear
merge using "B.dta"
Then, checked my data:
id group smoker
1 PS 1
2 PS 1
3 PS 1
4 PS 0
5 PS 0
6 PS 1
7 PS 1
8 PS 1
What have I done wrong?
Thank you kindly.
--
Michael McCulloch
Pine Street Foundation
124 Pine St., San Anselmo, CA 94960-2674
Tel: (415) 407-1357
Fax: (415) 485-1065
[email protected]
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