The Tax Policy Center released this table with information on how much in federal taxes (implicit or explicit) people would pay under the current policy and under 9-9-9.
The vast majority of people, as you would expect, would pay more under the plan. I call the net increase in money you give to Uncle Sam your Cain Pain and, for the handful of people out there where its relevant, the amount you would save the Cain Gain.
My Cain Pain would be around $2500. What's yours?