Hi,

I have a question regarding creating time trends to account for time effects before and after treatment. A reply to a post (click here for the post) I read suggested to subtract the year variable from the year of treatment to create a "time variable" which you can use to account for time trends. If you follow the method suggested by Clyde Schechter, I am confused as to how one can create a "time variable" for those groups who do not receive any treatment.

Thanking you,
Rohin