options nocenter pageno=1 linesize=90 nodate; data temp; do i=1 to 20; pred=1; outcome=1; output; end; do i=1 to 10; pred=0; outcome=0; output; end; do i=1 to 10; pred=0; outcome=1; output; end; run; proc logistic data=temp descending; model outcome=pred / clodds=both; run; proc logistic data=temp descending; model outcome=pred / clodds=both clparm=PL firth; run; proc logistic data=temp exactonly descending; model outcome=pred; exact pred / estimate=odds; run;