Dear Statalists,

(1) Can anyone help me check robustness for "xtrifreg" please? And how can I run simultaneous for "xtrifreg" Command? With "rifhdreg" Command, I can run simultaneous RIF regressions, but with "xtrifreg", I can not do that.
(2) Do you know any way to plot the quantile coefficients after running "xtrifreg" with fixed effect regression (xtreg, fe) in the same figure, please?

Thank for your help,