Pascal Stock wrote:
I have the problem that merging two datasets where the matches based
in the identifier ought to merge, as the identifier is identical in
the master and using dataset, some observations merge with _merge=3
and others with _merge=5 do not.
What could be the problem that the master data is disagreeing
(_merge=5)?
======================================================================
-help merge- tells that _merge=5 occurs with the -update- option
when there is a discrepancy between a nonmissing value in the
master dataset and the value in the using dataset. [D] merge
has this example:
. webuse updates
. save updates
. webuse original
. merge make using updates, update
. list, clean
make price mpg displa~t _merge
1. Chev. Chevette 3,299 29 231 3
2. Chev. Malibu 4,504 22 200 4
3. Datsun 510 5,079 24 119 3
4. Merc. XR-7 6,303 14 302 4
5. Olds Cutlass 4,733 19 231 3
6. Renault Le Car 3,895 26 79 5
7. VW Dasher 7,140 23 97 3
In the sixth observation, -mpg- was 26 in the master dataset and
25 in the using dataset, and that is what -merge=5 tells you.
Hope this helps
Svend
__________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000 Aarhus C, Denmark
Phone: +45 8942 6090
Home: +45 8693 7796
Email: [email protected]
__________________________________________
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
