运用xtcsd 检验时出错!
xtcsd,pesaran
Error: The panel is highly unbalanced.
Not enough common observations across panel to perform Pesaran's test.
insufficient observations
xtcsd , friedman
There are not enough common observations to perform Frees or Friedmand tests
xtcsd , frees 出现同样的错误!
求解?
非平衡面版数据中,怎么检测截面相关呢??