基准模型是
xi:xtreg wInvisetment wLgrowthcycle post postcycle0 wlev wlnage wROA wsize wtobinQ wtop1 wddrate wcashrate wcashflow wfixedrate i.year i.ind if m==1,fe r cluster(stkcd)
xi:xtreg wInvisetment wLgrowthcycle post postcycle0 wlev wlnage wROA wsize wtobinQ wtop1 wddrate wcashrate wcashflow wfixedrate i.year i.ind if m==0,fe r cluster(stkcd)


用bdiff 命令做组间差异检验
global xx "wlev wlnage wROA wsize wtobinQ wtop1 wddrate wcashrate wcashflow wfixedrate "

bdiff,group(m) model(xtreg wInvisetment wLgrowthcycle post postcycle0 $xx ,fe  cluster(stkcd))reps(200) bsample

命令可用
但是如果
bdiff,group(m) model(xtreg wInvisetment wLgrowthcycle post postcycle0 $xx i.year i.ind ,fe  cluster(stkcd))reps(200) bsample

就会出现错误