(draft) Social Security borrowing

This post will take a lot of refinement. It originated in a reply to an e-mail exchange and so lacks a certain amount of context, but I didn't want to waste the content. Feel free to criticize in the comments.

______________________________

Well 'a lot' may be an understatement. I seem to have doofed on the math, so I am going to return this one to draft mode until I can check the data better.

Plus I managed to delete the entire text in the process.