If I understand the current US system correctly, if you are a single person who is able to work and simply chooses not to do so, you may not qualify for any welfare whatsoever. If that is correct, a UBI would surely decrease your incentive to work.
Yes, this is the least convenient case. But UBI can still be a win in the longer run since it obviates the case for minimum wages and a lot of onerous regulation in the labor market. And let's be honest, if there are single folks who would be induced to exit the labor market under a (realistic) UBI, they're probably not getting much done at work in the first place!
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.