Arellano-Bond dynamic panel-data estimation Number of obs = 163
Group variable: firm Number of groups = 28
Time variable: time
Obs per group: min = 3
avg = 5.821429
max = 7
Number of instruments = 36 Wald chi2(8) = 200003.21
Prob > chi2 = 0.0000
Two-step results
------------------------------------------------------------------------------
roa | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
roa |
L1. | .3000986 .0034194 87.76 0.000 .2933966 .3068005
jiaozichan | -3.807051 .168478 -22.60 0.000 -4.137262 -3.47684
yanshengzi~n | -145.4201 29.81941 -4.88 0.000 -203.8651 -86.97511
mairufanshou | .2855277 .3085616 0.93 0.355 -.3192419 .8902974
kegongchus~u | -6.858728 .2380372 -28.81 0.000 -7.325273 -6.392184
chiyouzhiqi | 1.263883 .7422295 1.70 0.089 -.1908599 2.718626
changqiguq~n | -7.727417 .3745246 -20.63 0.000 -8.461472 -6.993362
fangdichan | -2.10997 .4575136 -4.61 0.000 -3.006681 -1.21326
_cons | 1.20943 .1024926 11.80 0.000 1.008548 1.410312
------------------------------------------------------------------------------
Warning: gmm two-step standard errors are biased; robust standard
errors are recommended.
Instruments for differenced equation
GMM-type: L(2/.).roa
Standard: D.jiaozichan D.yanshengzichan D.mairufanshou D.kegongchushou
D.chiyouzhiqi D.changqiguquan D.fangdichan
Instruments for level equation
Standard: _cons
.
. estat sargan
Sargan test of overidentifying restrictions
H0: overidentifying restrictions are valid
chi2(27) = 20.69545
Prob > chi2 = 0.8003
. estat abond
Arellano-Bond test for zero autocorrelation in first-differenced errors
+-----------------------+
|Order | z Prob > z|
|------+----------------|
| 1 | -2.338 0.0194 |
| 2 | 1.3783 0.1681 |
+-----------------------+
H0: no autocorrelation
7# wd3