First of all, as a society we're not cool with just letting poor people die in the streets. So while we don't provide housing, we do provide emergency room care. It's counterintuitive, but this begrudging little bit of help actually winds up costing society way more than if we just went the whole way.
Why? Well, it should come as a surprise to nobody that living on the street is kind of unhealthy, and that's before the depression and its accompanying substance abuse come into play. For example, Boston Health Care for the Homeless tracked 119 chronically homeless people for five years. In that time, those 119 people racked up an astounding 18,834 emergency room visits, despite the fact that 33 of them died and seven were placed in a nursing home during that time. In Washington in 2002, 198 individuals generated 9,000 emergency room visits, or a little under one a week. At a minimum of $1,000 a visit, that's a heck of a medical bill that those hospitals are trying to collect from a homeless person. Unless they have a really good day panhandling, that money is coming out of your pocket.
"You mean this won't cover my co-pay?"
Add in the annual cost of $24,000 if they take advantage of a shelter, plus the cost of the police to arrest and process those who misbehave (plus the round-the-clock housing, feeding and guarding they get once they're in jail), and it all adds up to a tidy sum for taxpayers to handle. Experts say it really would be cheaper just to house them and treat them.