Dear honourable members,

I am running a longitudinal data analysis using the gsem command according to the following exemple provided by stata guideline
https://www.stata.com/manuals13/semexample41g.pdf

I have a basic question, I don't really understand why its not recomended to run the xt command before the gsem as we do with other command like mixed or xtreg...?
Why we don't need to specify how the data order should be ?

could someone explain that to me ?

Thank you for your help.