dong713 发表于 2012-10-7 08:52 
有個疑問~ 可是Estimate the model for each firm under the assumption that 阿法(intercept=0). Do the
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在这个栗子里,你看price的系数
sysuse auto
regress mpg price //有常数项,即阿发
est store model1
regress mpg price,noconstant //无常数项
est store model2
suest model1 model2
test [model1_mean]price=[model2_mean]price