变量	ADF值	临界水平			P-value
变量	ADF值	1%	5%	10%	P-value
$\ln y$	−9.75279	−4.004425	−3.0989	−2.69044	0
$D (\ln X_{1}, 2)$	−3.966787	−4.200056	−3.17535	−2.72899	0.0144
$\ln X_{2}$	−11.1707	−4.004425	−3.0989	−2.69044	0
$\ln X_{3}$	−4.048888	−4.004425	−3.0989	−2.69044	0.0092
$\ln X_{21}$	−11.56387	−4.00425	−3.0989	−2.69044	0
$D (\ln X_{22}, 1)$	−6.522789	−4.12199	−3.14492	−2.71375	0.0003
$D (\ln X_{31}, 1)$	−6.033989	−4.05791	−3.11991	−2.7011	0.0004
$D (\ln X_{32}, 2)$	−5.61398	−4.12199	−3.14492	−2.71375	0.001
$D (\ln X_{33}, 2)$	−10.30117	−4.12199	−3.14492	−2.71375	0.0007