proc psmatch data=asdf1 region=cs;
class FLAG2 econ_status rural size ;
psmodel FLAG2(Treated="Y")=
n_10th_graders
prop_minority_10G;
match method=greedy(K=1) exact=(cate) stat=lps caliper=0.25;
output out(obs=match)=outgs2 lps=_Lps matchid=_matchID;
run;