[mitthrowaway2]

Why would it come from taxes, rather than simply from being printed?

The typical answer is "printing money causes inflation", but in the context of this feedback loop, it only causes exactly as much inflation as is required to cancel out the deflation caused by automation-induced layoffs and productivity increases. That's the magic of feedback.

But if it's because the resulting UBI would still be insufficient for welfare, we could also use taxes to fund a secondary "revenue-neutral" layer of UBI that taxes the rich and redistributes to everybody, but probably it makes sense to go in slower steps, seeing what level the primary UBI stabilizes at and then adding a secondary tax-funded one if the primary one isn't sufficient for both welfare and sustaining economic demand.

(The secondary UBI would probably still be somewhat inflationary, even though it's funded by taxes, just because poor people spend more of their money on things that are highly-weighted in the CPI, but the feedback loop will balance that out).

[JoshTriplett]

Ideally, the funding for it would on net come from the substantial economic boost created by UBI. More startups, more innovation, more job mobility, higher salaries (because people have more options), more education and training and skilled labor (because people have more ability to not work)...

[mitthrowaway2]

Indeed. I think one underappreciated economic boost would just be the greater economies of scale that so many production lines will be able to operate at when everyone can afford to buy their output!

[marcosdumay]

Because the printed money is way too little to create a social safety net.