在学习stata8。0中xtabond命令中,我看到手册中的相关例子
在这个例子中,n_it为因变量,公司雇员量
自变量包括
w_it ——真实工资
k_it ——总资本存量
ys_it——工业产出
yr1980,yr1981,yr1982,yr1983,yr1984为时间虚拟变量
针对下面的模型设定和命令以及结果,有一个问题美弄清楚想请教各位
xtabond n l(0/1). w l(0/2). (k ys) yr1977-yr1984, lag(2) twostep
note: yr1977 dropped due to collinearity
note: yr1978 dropped due to collinearity
note: yr1984 dropped due to collinearity
Arellano-Bond dynamic panel-data estimation Number of obs = 611
Group variable (i): id Number of groups = 140
Wald chi2(15) = 1035.56
Time variable (t): year Obs per group: min = 4
avg = 4.364286
max = 6
Two-step results
------------------------------------------------------------------------------
n | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
n |
LD | .6287089 .0904543 6.95 0.000 .4514216 .8059961
L2D | -.0651882 .0265009 -2.46 0.014 -.117129 -.0132474
w |
D1 | -.5257597 .0537692 -9.78 0.000 -.6311453 -.420374
LD | .3112899 .0940116 3.31 0.001 .1270305 .4955492
k |
D1 | .2783619 .0449083 6.20 0.000 .1903432 .3663807
LD | .0140994 .0528046 0.27 0.789 -.0893957 .1175946
L2D | -.0402484 .0258038 -1.56 0.119 -.0908229 .010326
ys |
D1 | .5919243 .1162114 5.09 0.000 .3641542 .8196943
LD | -.5659863 .1396738 -4.05 0.000 -.8397419 -.2922306
L2D | .1005433 .1126749 0.89 0.372 -.1202955 .321382
yr1979 |
D1 | .0151101 .0075654 2.00 0.046 .0002822 .029938
yr1980 |
D1 | .030858 .0123298 2.50 0.012 .0066919 .055024
yr1981 |
D1 | -.0096741 .0197077 -0.49 0.624 -.0483005 .0289522
yr1982 |
D1 | -.0155376 .015798 -0.98 0.325 -.0465011 .015426
yr1983 |
D1 | .0014798 .0117636 0.13 0.900 -.0215764 .024536
_cons | -.0038946 .0039242 -0.99 0.321 -.0115859 .0037967
------------------------------------------------------------------------------
Warning: Arellano and Bond recommend using one-step results for
inference on coefficients
Sargan test of over-identifying restrictions:
chi2(25) = 31.38 Prob > chi2 = 0.1767
Arellano-Bond test that average autocovariance in residuals of order 1 is 0:
H0: no autocorrelation z = -3.00 Pr > z = 0.0027
Arellano-Bond test that average autocovariance in residuals of order 2 is 0:
H0: no autocorrelation z = -0.42 Pr > z = 0.6776
命令中的l(0/1).w l(0/2) 中的(0/1).和(0/2)到底指得是什么意思啊?
好像手册中并没有明确、具体的解释。
感觉动态面板数据(gmm/dpd)分析方面,能够具体讲解stata操作和结果分析的资料太少了,理论分析倒是不少。
[此贴子已经被作者于2006-4-30 1:40:17编辑过]