If we get a universal basic income set equal to a living wage, then the "gig economy" can go back to being actual gigs, that is, people doing a bit extra to get a bit extra.
How many Americans are there (or just American adults)? 325M / 250M
What's those two figures multiplied together? 9.8T / 7.5T
What's the total federal tax revenues in 2016? 3.5T
To what multiple would we need to raise taxes to pay for such a program? Raise to 3.8x current taxation levels / raise to 3.1x current taxation levels.
All that assumes that basic prices wouldn't rise in an environment where money metaphorically fell like manna. (That $30K would have the same purchasing power as it does today, which seems unlikely.)
Adjust the assumptions as you like; IMO, there's no mathematically viable solution to a "living wage before the first hour of work".
And make it a pull tax system. Tax take = cost of UBI. Tax sources = income, financial transactions, static wealth and savings, land value, job-replacing automation.
Also, surely some percentage of taxpayers would stop working if they didn't need to work to live, so taxes would have to be raised even further.
And the higher the taxes go, the less point there seems to be in working. This could lead to more people dropping out of the workforce, which requires higher taxes on the remainder, and the cycle continues.
I don't know that it would happen this way, but if it did, it would destroy the economy.
Also automation, and taxes on automatically earned productivity.
And in fact, that money is likely to be more economically useful in the hands of ex-poor-now-comfortable people (who will use it to study and start their dream small businesses) than being frittered or sat upon by the very wealthy.
The rich would still get $30k, like everyone else. It's just that their increase in taxes would be bigger than that.
Most of the burden would fall on even richer people. There aren't many of these, but they make a lot of money.
But UBI would replace a lot of things currently funded mainly by rich people through either tax or philanthropy. Not just the whole welfare bill, lots of healthcare and law enforcement spending, but things like grants for the arts. Artists, musicians, etc would either live off their basic income or only require small payments for things like orchestral performances, commissions. Research where the cost of wages is a significant part of the cost (mathematics rather than rocket science) would enjoy a similar subsidy.
Many rich people spend a lot of time and money trying to either improve society or assuage their guilt for becoming rich in various anti-social ways. It might be somewhat worth it to them to have a society which they feel more positive about, but also have fewer threats to their well-being, such as from crime or populist politics.
You would expect some inflation, but tax receipts/GDP would also rise in line with inflation.
Some things would become much cheaper. For example, lots of people don't particularly want to live in run-down apartments in New Jersey. But they have to, because New York is where the work is. Those people might go and live much more cheaply elsewhere and have reduced housing costs.
The cost of artistic work would plummet, in line with the reduced demands of artists for money. (There are probably enough people who would want to make video games if they didn't have a day job that you could spend the rest of your life playing video games you enjoy for free.)
There wouldn't necessarily be much increased consumption of many things. If everyone eats dinner everyday, they would probably go on eating one dinner rather than three. If some people can't afford dinner currently, consumption and therefore prices, should rise. But some people not having food seems like a problem we should fix anyway.
Some things definitely would go up in price a lot. Things which have a high cost component of labour, and the people doing that labour don't particularly enjoy it. So you would have to pay people a lot to wait tables, and the cost of restaurants would reflect that. But there still might be lots of people who wanted to be maitre d's or helicopter pilots, at least for part of their lives. The flipside is that if you enjoy cheap food delivery, restaurants and taxis, you are currently being subsidized by welfare and other social care services which allow people to do crappy jobs for less money than it takes to live.
But the job they'd walk onto instead, is quite likely to be a return to personal food, retail, etc.
Like, Amazon might have trouble finding warehouse workers, but owner-operated bookshops would boom. McDonalds would have to go robot, but the cooks would be working at Mom's Diner.
Recognize that most people are going to be put off from the bare minimum arrangement, and that you don't have to pay people making above some arbitrary line, something like 6-7x the UBI.
Many of the social programs currently running could be shut down with UBI.
And all of these are based on the assumption that automation will continue to increase efficiency. Right now, it would be nearly impossible, especially with the legislation that exists. It's dependent on taxing the owners of businesses with high automation, recognizing that we're not far out from some truly massive automated systems, the most immediate being logistics and transport.
I agree with you (and would support an even lower UBI if it meant it had a chance for the math to work out). The "fight for $15" people probably disagree, though.
It's some weird Star Trek utopic vision, but I don't see it working. Not at scale. Especially not in the US, because to make it work you need tax money, and the US is tax-averse.