Both child support and alimony are not flat basic-necessity calculations, but are income based. The availability of a UBI doesn't change the fundamental premises on which those are built, or even make any significant impact on the formulas -- under the assumption that a UBI paid to the adults would be counted as each adult's income, and UBI paid for the child to the custodial parent(s) would be treated as joint income when the parents are together and income solely of the custodial parent in the formulas after a split, there would be no need to even touch existing formulas.
Furthermore, I have read up on the history of the American welfare program. It was dreamed up as a means to "help poor, single moms" at a time when intentionally getting pregnant out of wedlock was essentially unthinkable, so most poor, single moms were widows, not women who had given birth out of wedlock. The design of the program fundamentally changed the social contract and actively promoted the numbers of poor, single moms in the U.S., in part by making it less stigmatizing to have kids out of wedlock.
So, whether it is intended or not, if you pass a UBI, an awful lot of people will feel like deadbeat dads are not such a big deal and you will further change the social contract. The indicators I am seeing is that many of those changes will be negative changes rooted in a presumed lack of responsibility for our actions.
Welfare has the same problem with creating deadbeats but much worse, because if the father does actually pay child support or for that matter stays with the mother to raise the child, then the mother loses the welfare benefits. When you have two parents who are very poor but love their child it creates the unconscionable incentive for the father to leave so that the mother then qualifies for welfare while the father sends what money he can in cash under the table.
UBI at least improves the status quo by eliminating that.
To have children without the resources to provide for them is a terrible offense to the child. The single mom you describe made a mistake. Good things can come from bad decisions without trying to sugar coat bad decision making. Your scenario implies she had the child out of wedlock though, because....
> will no longer be made responsible for things like child support or alimony because, hey, the woman gets a check anyway
Certainly not, by my perspective. UBI is for individual needs provisioning. Your children supplant your own needs, and if either parent is exclusively on UBI they are in the unique situation where there is justification for them not having a minimum standard of living even with a UBI because they have committed themselves to taking care of their children first. In practice, that will rarely happen on the side of the custodial parent - the child would just suffer instead - but at least the one paying support would definitely not get out of it.
That is, of course, given that the parents started in a stable financial situation and just divorced, and had the reasonable financial means to afford children. If not, I have no sympathy. You have no right to have society give you money for succumbing to baser instincts, and it is a strong indicator of selfish behavior unfitting of good parents to have kids in such circumstances. And like I said, if the parents had the means, and just got divorced, of course the non-custodial parent should be paying in accordance with their original budgeting for the child, though I would mention that you would often want to the kid to go with whoever has the more stable income rather than who has the vagina more often than we do now (I have experienced through siblings the hell that is custody courts, and it is certainly completely broken today).
> Please do not make such sweeping statements about parents.
If you buy lottery tickets rather than pay your rent, I will make sweeping statements about your financial planning skills. If you splurge on a fancy dinner to then go hungry the rest of the week, I will certainly criticize that decision making as well. If you have children without confidence in your ability to provide for them, I will criticize you for just the same reasons. That does not make you a good or even a bad parent, it just makes you irresponsible.
But it does not matter how much you try to balance time vs money for your children after the fact. If you had them without the resources to provide the time and money they need they are negligent. The best intentions are meaningless when presented with reality, and at the macro-social level your intentions mean nothing next to the millions of other disadvantaged parents who probably mostly also had the best intentions, but led to childhood poverty being at its highest in 50 years in the states because we do not hold people accountable for terrible decision making with some of the most vicious costs possible - the damage poverty does to children is becoming more apparent every year, and it is a travesty to excuse their parents for it because some peoples bad decisions hurt others beyond themselves.
Scenario: Single mom of a child with special needs who is devotedly taking care of said child and does not have time to also work for money.
One of my fears with UBI is that I am hearing ideas posited that men will no longer be made responsible for things like child support or alimony because, hey, the woman gets a check anyway. And I think this is incredibly, seriously problematic.
Please do not make such sweeping statements about parents. Parenting is a very tough thing and money alone hardly makes one a decent parent. Studies have shown that there is as much neglect and abuse (and addiction) in rich neighborhood as in the ghetto. The best parents are typically middle class. They have consistently made choices to try to balance the need for money (which takes time) and the need to spend substantial time with their child(ren) in order to raise them.