[sokoloff]

The critical difference is the amount per person and the number of people included.

Welfare spending for 2020 is estimated to be around $1.9T, around $1.0T of which is means-tested, and $0.7T is Medicaid. Total federal receipts were around $3.4T.

If you believe that the entire adult population should receive the equivalent of a $15/hr minimum wage job that was worked 2000 hours per year, you need to fund $30K/adult. There are around 250M adults living in the US, meaning that paying each of them $30K would require more than twice the total federal tax receipts for this program alone. If you restrict it to citizens only (rather than all lawful residents), it's still basically double.

Even assuming you could cut every other federal function in half, you would still need to raise taxes by +150% (to 250% of current) just to pay for a $15/hr equivalent to adults only. Add in a smaller amount per child and you could be looking at tripling current tax levels. With the top marginal rate already higher than 33%, it's obvious that those tax increases will not hit only "the rich".

Then, does $30K/adult provide for everyone to "enjoy a more fulfilling life" given the inflation that would occur to pay for the UBI? I think it does not.

There is no doubt that UBI and taxation is more efficient; it's the simple multiplication that is a problem.

[overlords]

Something is wrong with that argument. Welfare + Taxation = Basic Income.

Already we have it, by definition - it's an equation.

So some part of your calculation is wrong.

Likely you're over-inflating the amount paid out (it's not going to by 15/hr person) and undercounting payments (maybe disabilty/housing/local programs).

UBI given at equivalent levels to today's welfare would be strictly cheaper because of the reduced adminstration cost.

(this though is different from the question of whether payments should be higher and paid by increased taxation.

And off-topic, but taxation doesn't need to be increased - it can be payed by helicopter money, but actually not cause inflation, because of geographic mobility deflating that aspect of the economy).