Also, the money used as basic income is not lost but will (mostly) stay in the economic system and stimulate growth. In most developed countries, introducing a universal basic income would require us to raise the tax rate to about 70 %, which does not sound ridiculously high given that it already is at 50 % in many countries (e.g. Germany). Also, the net effect on income would probably be positive for most people at the low end of the income distribution. People with higher incomes would lose money though.

The most interesting question (to me at least) therefore is how this new tax progression would change the incentives for people at the high end of the income distribution. Theoretically it should lead people that earn a lot of money to value their free time more, which in turn would make them want to work less. Another positive effect would be the reduction of economic inequality through the higher redistribution of money from high to low incomes. In Europe there are some countries that are a good example for this. Sweden notably has a very steep tax progression for people with large incomes, such that some people reportedly even reach marginal tax rates > 100 % (e.g. Astrid Lindgren https://en.wikipedia.org/wiki/Astrid_Lindgren). As a result, Sweden has one of the smallest income inequalities among countries in the developed world (the Gini coefficient there is 25 % vs. 46 % for the USA). Higher taxation of large incomes reduces income inequality, which I think is (mostly) a good thing.

The question is therefore not if it's possible (it probably is), but if people actually want it and think it's fair.

>$12,000/year per American adult who is not already on welfare or social security...

Is not what's being proposed by pretty much anyone.

$12,000/year per American adult who isn't already earning $X/year is how I understand it. A negative income tax, effectively.

Even if it's not administered that way (i.e., everyone gets a $1k check every month), then you raise taxes in such a way that every dollar earned means you earn more, but that by, say, $48k/year you're paying at least $12k/year in taxes.

The proposal is to pay all citizens the same amount. No means testing, no qualification except perhaps an age limit.

Individuals are not the only tax payers, and the wealthy do pay far more than $12,000 per year already.

Everyone does get the $12k, but you can effectively raise taxes to "cancel out" those $12k for the rich, maintaining the same effective tax rate for them.

My point is that you can adjust the tax code so that people over some threshold are paying $12k more than they used to, cancelling out the $12k of income. And counting people who are going to have their taxes raised by $12k in the overall cost is disingenuous. Below that threshold taxes will also likely go up, eating up some of the $12k there as well.

Then we agree :)