SAS Merge

[Astounding · Accepted solution]

Before you sort and merge, here is a statement you should apply to both data sets separately:

subject = compress(subject, , 'kd');

This will keep only the digits, and remove all other characters that may have crept into SUBJECT.  (As was mentioned earlier, there may be stray characters that don't appear when you examine the data such as a tab character.)  After that, you should be able to sort and merge with no problem.

Be sure to keep both commas in the key statement.