Correlated Random Effects - Hausman Test
Pool: GROWTH
Test cross-section and period random effects

Test Summary Chi-Sq. Statistic Chi-Sq. d.f. Prob.

Cross-section random 0.000000 5 1.0000
Period random 0.000000 5 1.0000
Cross-section and period random 0.000000 5 1.0000

* Cross-section test variance is invalid. Hausman statistic set to zero.
* Period test variance is invalid. Hausman statistic set to zero.
** Warning: estimated period random effects variance is zero.
请问是什么意思啊?应该选什么模型啊?