program define spregsarxt2
version 11.0
args lf XB Rho
tempvar rYW1 D0 D1
qui gen `D0'=0
qui gen `D1'=0
qui replace `D0' =1 if $ML_y1 ==spat_llt
qui replace `D1' =1 if $ML_y1 > spat_llt
qui gen double `rYW1'=`Rho'*w1y_$ML_y1
qui replace `lf'=-`D0'*(`rYW1'+`XB')+`D1'*($ML_y1-`rYW1'-`XB')-exp($ML_y1-`rYW1'-`XB')
end