In my view, there's some causation running in both directions going on here. There's not ever going to be a clean "X causes Y" in this model. For some percentag

In my view, there's some causation running in both directions going on here. There's not ever going to be a clean "X causes Y" in this model. For some percentage of the population, the fact that they were homeless led to their addiction problem. For some percentage of the rest of the population, their addiction either directly led to or significantly contributed to them becoming homeless. Debating about which one "is the one true cause" misses the point, and won't lead us closer to a solution.