I regress for the following panel fixed-effect model and leads to the result.
xtreg maroa osp, fe
maroa Coef. Std. Err. t P>t [95% Conf. Interval]
_cons .5585492 .0015033 371.55 0.000 .5556027 .5614957
The result shows that osp was dropped, can anyone help me what was happened and how can I solve this problem?