One again, apologies for the incomplete messages. It seems that I
inadvertently discovered a new keyboard shortcut for sending messages
in Yahoo Mail.
I work with household survey data and am looking for a way to assign
the mother's age to her children. The problem is that some
observations are missing. Take the data below:
hh id sex age mid fid
1 1 1 30 . .
1 2 2 30 . .
1 3 1 5 2 1
2 1 1 30 . .
2 3 2 5 2 1
There are two households (hh 1 and 2) with three household members
each (id 1 to 3). mid identifies a child's mother, fid the father. In
household 2, the mother (id 2) is missing. The usual code to assign
the mother's age therefore fails:
. bysort hh (id): gen mage=age[mid]
hh id sex age mid fid mage
1 1 1 30 . . .
1 2 2 30 . . .
1 3 1 5 2 1 30
2 1 1 30 . . .
2 3 2 5 2 1 5
The child in the second household is assigned her own age as the
mother's age because age[2] points to the wrong observation. My
solution is a loop over households and household members.
. gen mage2 = .
. levels hh, local(households)
. foreach hh of local households {
levels mid if hh==`hh', local(mothers)
foreach m of local mothers {
sum age if hh==`hh' & id==`m', meanonly
replace mage2 = r(mean) if hh==`hh' & mid==`m'
}
}
This yields the correct result but the loop is very time-consuming
with thousands of observations.
hh id sex age mid fid mage mage2
1 1 1 30 . . . .
1 2 2 30 . . . .
1 3 1 5 2 1 30 30
2 1 1 30 . . . .
2 3 2 5 2 1 5 .
I would appreciate suggestions for making the code more efficient.
Friedrich Huebler
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