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.
