In the 2021-22 fiscal year, when the homeless population was estimated to be 172,000, California spent $7.2 billion, which equated to nearly $42,000 per homeless individual.
This is why a housing-first policy is absolutely the only sane solution. At this rate, we can absolutely provide people adequate shelter.
If you multiply the HUD estimated census of homeless people by the average cost of housing it comes out to $11B annually, if by the average cost to incarcerate, then it's $30B/year. What's reasonable for administrative costs? Even if you figure 25%, that's $38B per annum max to house pretty much anyone who wanted it.
The Department of Housing and Urban Development has a budget of $40B. So just like healthcare, we already paying for it, we're just not getting it.
I don't know how that math really works though. Lots of homeless also have serious physical and mental health problems, addictions, and other issues. Housing is a first step but after that a lot more costs remain. Are those included in the $42K? And remember, California is more expensive than many other states, especially in the cities with lots of homelessness.
It's two different problems. UBI helps with poverty, and a lot of other social spending. Give everyone enough money for rent and tomorrow the price of rent is higher than what you're giving them. Housing is supply restricted, increasing the demand only makes it worse. What we need is a serious building spree.