Thanks for not jumping to assumptions in what I was saying. Nevertheless, it's certainly possible in principle for there to be a situation where the top earner

Thanks for not jumping to assumptions in what I was saying. Nevertheless, it's certainly possible in principle for there to be a situation where the top earners leave and it's better for society. As an absurd proof of concept: if the top holders of dollars are a handful of crooks who literally just extort the money from everyone else, and you get them to leave. In that situation, there's zero concern about them taking the dollars with them. You just continue giving everyone the UBI anyway, regardless of "revenue" and that means the dollar supply increases. This causes inflation, but everyone has more dollars to go along with that. Meanwhile, the crooks aren't getting more dollars, so their buying power is diluted. The entire effect amounts to returning buying-power to the rest of the citizens and reducing it from the crooks. It has no impact in any way on the productivity and real wealth in terms of goods and services — except that when you spread buying power out widely it will tend to support a much healthier economy… (all of this works whether the crooks leave or not, it's just even easier to dilute their buying power and political influence if they leave — except that what happens in most cases like this is the crooks wage real physical war to maintain their wealth and power rather than just sulk and go away). So, the top "earners" moving away means reduced influence from them in all sorts of ways monetarily. But if those people happen to actually be important to the economy rather than mere leeches, then we may see a serious downturn as a result, albeit potentially offset somewhat by the economic benefits of giving more buying power to those who will use it for productive economic ends (fixing their houses, caring for kids, buying new goods) where the wealthiest folks just save it and don't need thousands of pairs of pants etc. In short: it's absurdly simplistic to believe either that UBI necessarily leads to economic boon or catastrophe. It all depends on tons and tons of details which way it goes (of which the productive vs leech status of wealthiest folks is just one of those details).