st: RE: additional observations when merging data sets

[Joe Canner <jcanner1@jhmi.edu>]

Katie,

Please provide an example of the command(s) you are using, as your description is confusing and seemingly contradictory ("I select to keep unmatched data from memory" or " I'm choosing to drop unmatched data"?).

Thanks,
Joe Canner
Johns Hopkins University School of Medicine

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Katie Farrin
Sent: Monday, December 02, 2013 7:01 AM
To: statalist@hsphsun2.harvard.edu
Subject: st: additional observations when merging data sets

Good morning,

I have a general question I was hoping someone would be able to help with.  I have household data that I would like to merge with corresponding community level data, and am using a pairwise merge by community.  I select to keep unmatched data from memory, as my sample of households does not include all communities surveyed.  However, when I merge the data I get 50 additional observations and I am not sure why this is happening (my original data set has 2056 observations and the merged set has 2106).  If I'm choosing to drop unmatched data from the new file, what is going on to create additional observations?
Each household should have only one associated community ID.

Thank you!

Katie
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/