使用的是非平衡面板数据
命令是:
xthreg2 ROA growth Lev Cash Statecode hefin age ,rx( RDrate) qx( chanpinshichang) trim(0.01) thnum(2) bs(300)
结果显示:
There exist time-invariant individual(s) (maybe only one obs): ROA growt Lev Cash Statecode hefin age RDrate chanpinshichang Year must have multiple distinct nonmissing values
删除所有控制变量后
xthreg2 ROA ,rx( RDrate) qx( chanpinshichang) trim(0.01) thnum(2) bs(300)
结果显示:
There exist time-invariant individual(s) (maybe only one obs): ROA RDrate chanpinshichang
<istmt>: 3499 thestm2() not found
这是为什么?万分感谢!


雷达卡




,我的y是宏观的,x是微观的,一直这样报错
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