06-20-2015 04:18 AM
Matching with replacement / Matching without replacement
Test firm Matching firm
A 22 2009 Size=$42billion C 22 2009 Size=41billion / C 22 2009 Size=41billion
B 22 2009 Size=$40billion C 22 2009 Size=41billion / D 22 2009 Size=41.5 billion
To create a matched sample, I need to find a matched firm for 'A' and another for 'B'. If I'm matching on specific year (2009), I need to find with closest to 50billion for 'A' from the same sic code in 2009. Again the same for 'B'
I give an simple example of 'Matching with replacement' and 'Matching without replacement'. My desire output is 'Matching without replacement'
This means that once SAS program finds a matched firm, it cannot use the same firm to be matched another test firm. (in the same fiscal year & same sic code).
create table matching1 as
select a.*, b.*, abs(a.size - b.sizes) as diff
from mergedata_6 a, mergedata_5 b
where a. fyear = b. fyr and a. sic = b. sic1
group by b.fyr ,b.sic1, b.ciks
having calculated diff=min(calculated diff);
PROC print data=matching1;
However, my SAS code just works as 'Matching with replacement' case. Please give some help for solving this problem.