The lack of housing may in fact be a 'cause'. Once you have a 'safe space' of stability, you might be able to start to work on those other problems. 'No home'

The lack of housing may in fact be a 'cause'. Once you have a 'safe space' of stability, you might be able to start to work on those other problems. 'No home' is an impossible place from which to make any progress at all. There is definitely an issue with 'tragedy of the commons' etc. but there's also no doubt in my mind the 'home first' thing works. That said - here in Canada, means tested welfare is enough to pay for rent, food - and basically nothing more. But a considerable number of people in my neighbourhood in Montreal chose 'crack + sleeping rough' over 'flat + food'. Even in the winter. There is 2 feet of snow outside and 1 guy sleeping rough less than 100m from where I write this, outside the clinic. Less than 2 blocks away, there are flats for $450/month $CDN, and they are not bad at all. (It's a very mixed neighbourhood). I suggest it's a tricky problem and that UBI-ish solutions might not work here, and that it probably needs to be a 'programme' i.e. combined with social workers, monitoring etc..