Hello everyone,

I am trying to make an event study graph. For this I need to pool my post and pre treatment years.
So if I have:
Code:
 input municipality year treatment 1 93 0  1 94 1 1 95 0 1 96 0 2 93 0 2 94 0 2 95 1 2 96 0 3 93 0 3 94 0 3 95 0 3 96 0 end list
How do I get:
Code:
input municipality year treatment t 1 93 0 -1 1 94 1 0 1 95 0 1 1 96 0 2 2 93 0 -2 2 94 0 -1 2 95 1 0 2 96 0 1 3 93 0 . 3 94 0 . 3 95 0 . 3 96 0 . end  list
This is my first post here, so if I need to provide more info or do something differently please tell me so!
Thanks!