I’d argue what is happening in the US is already a country wide test. People are taking the benefits rather than going to work for marginally more. It is not a good outcome for society. And high benefits countries like France know that very well. Lots of harder job openings there are never filled even though the country has a permanent large unemployment. I like the idea of UBI on paper but I feel it is counterproductive in practice.
UBI is supposed to be universal. Under UBI the choice would be get the 'free money' and also work or just get the 'free money'. Under unemployment insurance, you generally can't keep getting benefits when you are working, so it's not the same choice.
This is a challenge with a lot of benefits programs; the change in income often doesn't seem to justify the change in labor. If you get the same UBI payment regardless of if you're working or not, the disincentive to work, because it ends your benefit isn't there; of course, the disincentive to work, because working is work is still there.
That’s not the point. The point is that you have a basic revenue doing nothing, and only a marginally higher revenue if you work. How you segment these revenues isn’t the problem.
