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Re: st: merge within a range


From   Phil Schumm <pschumm@uchicago.edu>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: merge within a range
Date   Thu, 16 Sep 2010 16:51:59 -0500

On Sep 16, 2010, at 3:55 PM, Richard Goldstein wrote:
I have the following merge problem. In one data set I have a start date and and end date (and, of course, several other variables); in another data set I have a particular date. I want to merge the two data sets with a match occurring if the "particular" date in data set 2 is between (or equal) to the startdate/enddate in data set 1.

An obvious kludge is to expand the first data set and fill-in the dates to be consecutive. If possible, however, I prefer not to do this and am looking for any suggestions.


Merge by all of the other variables first, and then just drop the resulting observations that don't meet your condition (i.e., for which the date is not between your start and end). If the other variables together do not uniquely identify the observations in either file, you'll need to use -joinby- instead of -merge-.


-- Phil

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