面板数据作单位根检验时,有的变量平衡,有的不平衡。做了一阶差分后都平衡,但是接着做协整时出现了以后一下情况。这是怎么回事?哪一步操作出了问题?
Pedroni Residual Cointegration Test
Series: LNZL1? IMP? LNRDH? LNRDM?
Date: 05/03/15 Time: 10:55
Sample: 2004 2013
Included observations: 10
Cross-sections included: 31
Null Hypothesis: No cointegration
Trend assumption: No deterministic trend
Lag selection: fixed at 1
Newey-West bandwidth selection with Bartlett kernel
Alternative hypothesis: common AR coefs. (within-dimension)
Weighted
Statistic Prob. Statistic Prob.
Panel v-Statistic NA NA NA NA
Panel rho-Statistic 8.161896 0.0000 NA NA
Panel PP-Statistic -3.361463 0.0014 NA NA
Panel ADF-Statistic 1.960072 0.0584 NA NA
Alternative hypothesis: individual AR coefs. (between-dimension)
Statistic Prob.
Group rho-Statistic NA NA
Group PP-Statistic NA NA
Group ADF-Statistic NA NA
Cross section specific results