STATA分组回归检查系数差异时,test [b1_mean]x2 = [b2_mean]x2,却总是显示equation [b1_mean] not found,该怎么解决?
我的回归是这样的
tobit y2 x2 size roa if a>=0, ll(0)
est store b1
tobit y2 x2 size roa if a<0, ll(0)
est store b2
suest b1 b2
test [b1_mean]x2 = [b2_mean]x2