Every study shows that the overriding cause of homelessness is the lack of affordable housing.
Is there drug use in homeless populations? Of course, there’s also a ton of alcohol use as well. Is it the cause of homelessness? No.
Because we have statistics from other states with much higher drug abuse and OD stats that have lower rates of homelessness, because the driving cause of homelessness is not being able to afford a home.
Hell even HN had a post on this a week or so ago, the dominant factor - more than laws, environment, social support - is housing costs.
The other thing people don’t acknowledge that the denser your population the more compact - and so pronounced - the homeless populations become. A few years back there was an article about how Boise didn’t have the SF homelessness population due to punishing the homeless. Except statistically they had basically the same number, but doesn’t have anything like the population.
Places with bad weather definitely have homeless populations. In the larger view, look at Chicago and New York City.
In the smaller view, look at pretty much any mid-size hub town in the Midwest, or Indiana at least. All of them I've lived in have shelters (the smaller towns usually don't). Food pantries of different sorts are fairly common too, even in small towns. A fair number of these are run by churches who have a mixed track record of how they treat folks staying there (turning away queer folks, forced work or taking possessions, etc).
It isn't like anywhere actually has year-round beautiful weather - not the sort that makes you eschew housing. Some places you just don't have to worry about freezing to death most nights.
One thing about both the studies you reference and studies I reference is that they're both correlative. Not causative. A causative study is virtually impossible here.
One possible causal chain: Drug use leads to less money, leads to no house in high cost areas.
Another possible chain: No money, leads to no house in high cost areas, leads to drug use.
There's actually infinite possibilities because the causal source can come from an unknown variable that we didn't reference here.
https://www.cdc.gov/nchs/pressroom/sosmap/drug_poisoning_mor...