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Re: st: Preventing 'spreading' on merging files
At 12:28 31/03/2004, you wrote:
I have a data set with around 90,000 observations and I am merging it with
Sounds like your key-variable is not unique in the using dataset, so some
records in your master set match with more than one record in the using
set, and therefor get duplicated.
another dataset with around 3 million observations. However, when I merge the
two, the number of '3s' in the _merge variable exceeds the 90,000 in the
file by a few thousand, indicating that there is more than one observation in
the using file for some of the observations in the working file.
Does anyone know if it is possible to prevent Stata from picking up the
additional observations from the using file (i.e., constraining the
merged to the 90,000 in the working file)?
Maybe you might want to take a look at mmerge.ado, which adresses these
issues more directly then the built-in merge command.
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