Robotic automation of any sort doesn't occur in a vacuum.

If 50% of the jobs in a field are automated, in the near term you still have 100% of the former labor looking for that job, pushing salaries down towards their minimum, thereby reducing the cost effectiveness of further automation.

Though of course (without passing a value judgment on such policies) minimum wages set an artificial lower bound on the cost of human labor here, and this kind of low-skill work is inexpensive enough that hitting that bound is likely (vs., say, automating legal work), especially as minimum wages rise. For some industries getting to the point that near-100% automation is cheaper than $15/hour for humans is totally plausible to me.

Exactly. The differences between minimum wage and UBI is fascinating, but I didn't want to bring it up above.

To me, minimum wage says "if you work, then you should at least able to support yourself on your income$." UBI+ says "if you work, you must find greater fulfillment than mere sustenance in your work."

Personally, I can't see minimum wage applying to anyone receiving UBI. Although it might make sense to have a "less than minimum wage" tax that helps fund the UBI directly.

$ Abstracting away actual amounts and whether or not they're enough

+ Market adjustments aside

At the same time, an UBI will make it so people still don't care to perform certain below-current-minimum-wage jobs. E.g. if I were on UBI, and I effectively earned $15/hour through it, I still wouldn't bother looking at jobs unless they paid, say, $5/hour or more.

I think that's one of the most fascinating questions about UBI though. Hypothetically, if you had UBI and were content at that level of consumption, what would you do? If I absolutely loved animals, I can certainly see working in a pet store for $2/hr or a pittance.