标签: stata
为什么输出(945.8707):
foreach var in ann_grinc ann_tax ann_dispinc ann_exp ann_pens ann_mort ann_education { mean `var' if workers==1 & kids==1, over(bands) nol }
与此输出(934.1959)不同:
mean(ann_tax) if workers==1 & kids==1 & bands==2