There's no "demand". Basic means setting a base income level. That's it. It's disingenuous to assert that you can't have UBI below some threshold. You could

There's no "demand". Basic means setting a base income level. That's it. It's disingenuous to assert that you can't have UBI below some threshold. You could set UBI at $50 per month ($300 per year). By itself, this isn't enough to survive on in a developed country, and the amount would be negligible for almost everybody. But if you're in a situation where $50 per month is going to make a material impact to your life, then you really need it. UBI disproportionately helps the most desperate. That's the point.