Hello, I'm in work of doing propensity score matching and got a problem. I'm using 'proc psmatch' and the code that i made is like below. proc psmatch data=ps11 region=cs; class voluntary; psmodel voluntary=lag_block lag_for lag_size lag_lev lag_sales_grw lag_roa lag_boardsize lag_board_ind lag_audit_comm_size; match method=optimal(k=1) distance=lps caliper=0.25; output out(obs=all)=psmatch matchid=_matchid ps=propensity_scores lps=logit_propensity_scores; run; Running with the above code i don't get any matched id. Also, the message of 'ERROR: A feasible optimal fixed ratio matching that has the specified parameters does not exist.' keep comes up. Does anyone who knows what is the problem and can fix it please? Sincerely.
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