I need to match my dataset based on Marketcap , I used this code and I constantly get the error of "the support frgion does not exist. proc psmatch data=propensity_scores region=cs; class Nonover; psmodel Nonover(treated='Yes')= overlap Marketcap; match method=optimal(k=1) stat=lps caliper=0.25; output out(obs=match)=outEx1 matchid=_matchID; run; here is the code I used . is there anyone can help me please ... View more