stata官网上的回答:
The "o." prefix is used by Stata for a variable that's been omitted because of collinearity or whatever. If you reestimate but omit the dropped variable by hand, xtoverid should then work.
by https://www.stata.com/statalist/archive/2013-04/msg00833.html
stata官网上的回答
The "o." prefix is used by Stata for a variable that's been omitted because of collinearity or whatever. If you reestimate but omit the dropped variable by hand, xtoverid should then work.
By: https://www.stata.com/statalist/archive/2013-04/msg00833.html