st: Nearmrg deleting unmerged observations

[Lara Loewenstein <lionstone@gmail.com>]

I'm using nearmrg to merge two datasets by street address. But I want
an approximate merge for the street number while an exact merge for
the street name. I also have multiple cities in the master dataset,
while only one city in the using dataset, so I want to merge in the
using dataset for that one city while keeping the unmerged
observations in the master dataset. My code looks like this:

nearmrg street city using "UsingData", nearvar(stnum) limit(10)
genmatch(using_stnum) update

The problem is, that when I do this, nearmrg automatically deletes all
the unmerged data, so all i'm left with is a subset of the city in the
using dataset that managed to merge with the master data.

How do I get nearmrg to keep all the observations, both merged and
unmerged? I tried adding the keep option from the standard merge
command, adding keep(1/5) since I'm updating a variable as well, but
that caused nearmrg to delete all the observations and left me with an
empty dataset.

Many thanks.

Lara Loewenstein
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