下面是我用stata做出的结果,想请问一下其中的Wald chi2(5) = 1418.23,是不是就是用Wald检验来测试面板数据模型中是否存在个体随机效应的结果?那么它是否显著呢?还想请问一下,如何用stata做变量的描述性统计,包括均值、标准差、最大值、最小值等?另外,表中的z统计量是什么呢?相当于截面数据或时间序列数据中的t统计量吗?谢谢!
Random-effects GLS regression Number of obs = 11558
Group variable (i): company Number of groups = 1441</FONT></P>
R-sq: within = 0.1732 Obs per group: min = 2</FONT></P>
between = 0.0029 avg = 8.0</FONT></P>
overall = 0.0458 max = 9</FONT></P>
Random effects u_i ~ Gaussian Wald chi2(5) = 1418.23</FONT></P>
corr(u_i, X) = 0 (assumed) Prob > chi2 = 0.0000</FONT></P>
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y | Coef. Std. Err. z P>|z| [95% Conf. Interval]</FONT></P>
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payout | .1412676 .0080563 17.54 0.000 .1254776 .1570576</FONT></P>
debt | .0000807 .0003688 0.22 0.827 -.0006421 .0008035</FONT></P>
size | .0888866 .0044324 20.05 0.000 .0801991 .097574</FONT></P>
roa | -.0055888 .0003076 -18.17 0.000 -.0061916 -.0049859</FONT></P>
year | .006685 .001268 5.27 0.000 .0041998 .0091702</FONT></P>
_cons | -14.46488 2.505555 -5.77 0.000 -19.37567 -9.554079</FONT></P>
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sigma_u | .14805566</FONT></P>
sigma_e | .26928236</FONT></P>
rho | .23212616 (fraction of variance due to u_i)</FONT></P>
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