请教大家一个问题:本人想在回归方程中加入行业虚拟变量作为控制变量,于是参照年度虚拟变量的生成方法,使用tab id,gen(id)命令生成了行业虚拟变量,id1,id2······id10.但是在做回归时却出现共线性问题:note: id2 omitted because of collinearity
note: id3 omitted because of collinearity
note: id4 omitted because of collinearity
note: id5 omitted because of collinearity
note: id6 omitted because of collinearity
note: id7 omitted because of collinearity
note: id8 omitted because of collinearity
note: id9 omitted because of collinearity
note: id10 omitted because of collinearity