There should not be any universal basic income, at least past puberty. Instead, on and after age of the average onset of puberty (10-13), universal basic income should be replaced with sterilisation/non-procreation basic income (SBI/NPBI henceforth). Man should be given SBI for having a vasectomy and not getting vasectomy reversal surgery. Woman should be given NPBI for installing IUD and keeping it. Obviously, vasectomy and IUD will be paid by the government. In other words, vasectomy basic income and IUD basic income. If you are so poor to need to rely on government welfare of UBI, then you shouldn’t procreate. With SBI/NPBI, every other form of government welfare should be abolished.
(I think requiring tubal ligation for women are too much because it require general anesthetics and costly)