"My previous comment wasn't considering that BI would replace the current means-tested welfare programs" That's exactly what it would do. If, as in your hypot

"My previous comment wasn't considering that BI would replace the current means-tested welfare programs" That's exactly what it would do. If, as in your hypothetical situation, someone spends their basic income too fast, they'll just have to wait until the next week/next month to get their next installment. If they can't manage that, then there are likely to be other contributing factors, such as drug addiction or mental illness, in which case you can offer alternative forms of support.