Hello and thank you for taking the time to help.

I am working on an analysis of voter roll purges and want to create a new variable to regress against CCES turnout data but I haven't used stata in over a year and my quant class didn't cover this type of variable generation.

The variables I have consists of the total number of removed voters and the total number of registered voters for 50 states (minus a few removed for lack of data) and election year (2010, 2012, 2014, 2016, and 2018). I'd like to divide the number of purged voters (total_removed) in a year (for ex. 2018) by the total registered voters (total_reg) in the prior year (in this case, 2016) in each state. I'm pretty far out of my depth and I've guessed at a few formulas but nothing's worked.

Do I need to create dummy variables for each pair of years? As in, create a variable for each 2018 - 2016 pair then 2016 - 2014 etc.? That's the only thing I can think of but that also sounds very time intensive and clunky for my reg.

Thank you for any help you can provide.