John Baj <jbaj@NIU.EDU> wrote:
>> What I need to do is to build a comparision group
>> for the welfare population from the non welfare
>> population (matched pairs). For this comparison
>> group, I am trying to match each job spell of welfare
>> recipients to a job spell of a non recipient who
>> began working for same employer at the same
>> time and for approximately the same wage (using
>> the earnings variable as a proxy) as the recipient.
The BioStats folks at Mayo Clinic have kindly made a macro available to the public that I believe will do what you describe (a post-observational assignment of control cases) ....check out "Match" at http://www.mayo.edu/hsr/sasmac.html
Computerized matching of cases to potential controls.
The purpose of this macro is to match 1 or more controls
(from a total of M) for each of N cases. The controls may
be matched to the cases by one or more factors(X's).
Jon Kosanke & Erik Bergstralh [28/OCT/1999]
Gainesville FL USA