Undoubtedly there are edge cases where that's true. But as an argument for UBI it works only if the cost savings from labourers being willing to undercut market price of robots in a UBI-era world across the whole economy exceeds the net cost of making welfare payments to a vast number of other people previously ineligible for them.

At present, the numbers of people claiming welfare because their skillset has been superseded by automation are vastly exceeded by the number of people on federal minimum wage jobs or choosing not to be employed...

And that's even before you look at the distributional impact of the subsidy (the benefits from cheaper labour tend to accrue to a subset of business owners; the cost of subsidising it is shared across all taxpayers, with the net burden probably falling on middle class wage earners)

If a government were to decide that preserving jobs in a particular automation-threatened industry/locale were worthwhile due to the difficulty of finding alternative occupations, a targeted subsidy per job would be far more efficient

I guess it's more of an argument for a universal wage subsidy, but I'd be happy with UBI as well.

I've been thinking about UBI a lot. Who's going to pay for it? Certainly not the big tech companies. They barely pay any taxes now, and they're the ones who stand to gain the most with automation.

Don't forget that if nobody gets paid then they can't consume all the wonderful output the robots produce.

Ideally, it would be financed using a mix of fiat currency and taxes. Then it could take the place of debt growth for building the monetary base. If inflation becomes too rapid, the mix would be tilted more towards taxes. If deflation hits, the mix would be heavily tilted towards fiat.

"A mix of fiat currency and taxes" is somewhere between poorly described and downright incoherent. Fiat currency is a thing you can use for money, taxes is a way of gathering money (whether its fiat currency or not) for the government.

Do you mean a mix of printing money and taxes -- e.g., just outright abandoning the idea of independent central banking and separation of monetary policy from fiscal policy and using a mix of directly printing money and regular taxation to fund the benefit?

If so, I think that's a poorly conceived idea that, in the best case, has no advantages from running monetary policy independently with similar priorities to those that drive it in principle now (managing inflation and unemployment), while paying UBI out of general government funds while funding the government through a mix of taxation and debt as now.

A sufficiently low UBI (survival, not comfortable survival with all kinds of nice-to-haves) would be wage subsidy (or microentrepreneurship subsidy, or subsistence farming subsidy) in all but the most extreme cases of zealous frugality combined with a heavy disinclination to work. Excess money beyond survival is a very strong incentive, much stronger at least than replacing survival level welfare with survival level earning, which is what existing systems routinely expect to happen.