sophiafinn 发表于 2012-5-11 09:52 
hope this helps~
可以请教下 为什么我的stata回归结果中没有difference in hansen结果,谢谢
Dynamic panel-data estimation, two-step system GMM
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Group variable: region Number of obs = 372
Time variable : year Number of groups = 31
Number of instruments = 133 Obs per group: min = 12
Wald chi2(2) = 955.12 avg = 12.00
Prob > chi2 = 0.000 max = 12
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| Corrected
cz | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
cz |
L1. | .7639537 .0989087 7.72 0.000 .5700962 .9578113
gdp | .0893422 .0196248 4.55 0.000 .0508784 .127806
hp | .0780378 .0258245 3.02 0.003 .0274227 .1286529
_cons | -77.56584 41.69904 -1.86 0.063 -159.2945 4.162779
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Instruments for first differences equation
Standard
D.(hp D.hp)
GMM-type (missing=0, separate instruments for each period unless collapsed)
L(1/.).(L.cz gdp)
Instruments for levels equation
Standard
_cons
hp D.hp
GMM-type (missing=0, separate instruments for each period unless collapsed)
D.(L.cz gdp)
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Arellano-Bond test for AR(1) in first differences: z = -3.82 Pr > z = 0.000
Arellano-Bond test for AR(2) in first differences: z = 2.18 Pr > z = 0.029
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Sargan test of overid. restrictions: chi2(129) = 354.55 Prob > chi2 = 0.000
(Not robust, but not weakened by many instruments.)
Hansen test of overid. restrictions: chi2(129) = 30.51 Prob > chi2 = 1.000
(Robust, but weakened by many instruments.)