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st: RE: Preventing double counting
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
st: RE: Preventing double counting
Date
Thu, 8 Dec 2011 12:45:40 +0000
In addition to Brendan's suggestion, you can check consistency like this:
gen first = min(orig, dest)
gen second = max(orig, dest)
bysort first second : assert _N == 1 if first == second
by first second: assert _N == 2 if first < second
by first second : assert netmigration[1] == -netmigration[_N]
See also
SJ-8-4 dm0043 . Tip 71: The problem of split identity, or how to group dyads
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox
Q4/08 SJ 8(4):588--591 (no commands)
tip on how to handle dyadic identifiers
Nick
[email protected]
Michael Betz
I have state-to-state migration data that is as follows:
orig_state dest_state netmigration
1 1 0
2 1 25
3 1 .
1 2 -25
2 2 0
3 2 44
1 3 .
2 3 -44
3 3 0
There is an origin state, a destination state, and net migration between the two. I don't want to double count net migration so I only want to keep a single observation for each state pair. Does anyone have any suggestions about how I could get rid of the second observation that gives me the negative net migration of the first observation?
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