代码   
bdiff, group(NGD) model(reg Dcash CFO Size Q DStd DNwc CapEx Growth Fshare PPE i.year i.ind) rep
> s(1000) seed(100) bs first detail
报错：
Note: The numbers of effective independent variables in Group1 (NGD=0) and group2 (NGD=1) are not
> equal
This may occur because you use the factor variable to indicate the dummy varaibles