Hi Mr. Clyde Schechter,

I am working with a panel dataset containing the 50 states (+D.C) containing information the states' stress abstinence policy for teenagers for the years 2003 to 2012. I need help on how I can create 1. variable indicating the control and treatment groups and 2) pre and post-treatment (pre-being before the stress abtsinence policy was enacted, and post-being years after the enactment)so that I can carry out a difference in difference estimation in Stata. I already have a variable that says stress abstinence (equal to 1 for stress, and 0 elsewhere).

I'd appreciate any help. Thank you.