. mlogit promotion term term2 age education gdprateterm intenrateterm consumptionrateterm
no observations
r(2000);

. mlogit promotion term term2 age education gdprateterm intenrateterm consumptionrateterm, vce(robust)
no observations
r(2000);

. mlogit promotion term term2 age education gdprateterm intenrateterm consumptionrateterm, vce(robust)
no observations
r(2000);

. xtreg promotion term term2 age education gdprateterm intenrateterm consumptionrateterm i.pro i.year,fe r
no observations
r(2000);

没有观测值
你先看看哪些变量是否有数据
是否有字符型的
如果没有问题就先放入一个变量回归，然后再放第二个，看看到底是哪里出的问题