I'm not at all convinced of UBI, but does your math include removing all the tax that pays for benefits that would no longer be needed such as unemployment, social security, etc.? It seems removing those benefits would reduce the tax burden significantly.

That's a nice theory at steady-state, but how do you get there?

If UBI is less generous than Social Security, then you have a problem.

You have lots of retirees (15% of the population) who have been promised Social Security and have retired on that basis. You also have lots of people that are relatively near retirement that will be in the streets with pitchforks if you threaten their benefits: Social Security is the original third rail of American politics - touch it and you die.

You basically need to allow people to choose whether to get UBI or stay in Social Security. This creates a gigantic fiscal bulge because you end up funding Social Security for everyone for whom it represents a better deal.

If UBI is more generous than Social Security, then you also have a problem. You are effectively exchanging it like-for-like and there's no extra tax take to spread around.

It does not, but I also don't see any way that a $750/mo provides a viable path to remove a $1500/mo average (and 150+% of that for many) Social Security payment for people who contributed to FICA over their entire working lives and properly planned on that money as part of their retirement finances.

Morally and politically, I can’t see how to make UBI replace social security. You might be able to make reduced UBI payments to seniors, but at some point you have to ask “what does the U in UBI stand for?”

> but does your math include removing all the tax that pays for benefits that would no longer be needed such as unemployment, social security, etc.?

Earned benefits like unemployment, disability, and social security are usually not targeted for replacement by UBI, and it is dubious that it makes them unnecessary (especially UI/DI, given benefit levels) unless it is at a very high level.