本人初学,看了楼主的笔记,初次尝试做了Hausman检验,觉得应该用固定效应模型,检验结果如下,请各位指正下:
---- Coefficients ----
| (b) (B) (b-B) sqrt(diag(V_b-V_B))
| fe re Difference S.E.
-------------+----------------------------------------------------------------
cheng | -.1394439 .1784939 -.3179377 .0313292
qianli | -.0846376 -.1387043 .0540667 .
kesan | .2595918 .37885 -.1192582 .
nong | .5415334 -.4032474 .9447808 .1228051
weih | .0476976 .1295922 -.0818946 .1730931
jiao | -.5796141 .3490597 -.9286738 .1498178
xing | 1.295428 -.3439792 1.639407 .2239614
------------------------------------------------------------------------------
b = consistent under Ho and Ha; obtained from xtreg
B = inconsistent under Ha, efficient under Ho; obtained from xtreg
Test: Ho: difference in coefficients not systematic
chi2(7) = (b-B)'[(V_b-V_B)^(-1)](b-B)
= 115.52
Prob>chi2 = 0.0000
(V_b-V_B is not positive definite)