I think too many believe as HighwayMan does that the majority of the homeless are mentally ill or drug abusers...
Quincy, I did not base my comment on passing contact with a few people in the homeless community. I based it on dealing with the same people over and over again over the course of years. Hundreds. Not just in NYC, but in neighboring counties as well. Every one of my co-workers has stories about the legions of "regulars" that they deal with on a daily basis.
I've sent many to the hospital over the years for obvious drug and alcohol intoxication. Even when they return after a day or two and seem to be "sober" they exhibit very abnormal behaviors. Help is always offered and in almost every case refused.
I can now recall only one case where the people involved did not appear mentally ill or intoxicated. I responded to a complaint of a man and woman sitting in front of a train station with luggage for days at a time, apparently traveling but never going anywhere.
I made contact with them and ascertained that the husband was a paralegal who had gotten laid off and was unable to find employment - he was on the older side. The wife never worked and their well-off family refused to help them by taking them in for a few months to allow them to get on their feet. They were caught in a bad spot and were unable to get real help. I made some contacts with county homeless services on their behalf and the last time I spoke to them the husband said he had a job interview. I never saw them again so I like to think they made out alright. They were the exception to the rule.
Every day before taking my present administrative assignment I was in contact with dozens of homeless in the subways, train stations, on the streets, etc. As far as I'm concerned while housing is an important issue, mental health care is a much bigger factor, and the City of New York has failed miserably there (as well as the other counties I work in, to a lesser extent). The mental health organization founded and led by the mayor's wife is unable to account for over 3/4 of a billion dollars of their funding, and has had no success in making things even minimally better.
Think what you will - I have no idea what it's like anywhere else in the country, but I'll stick with my assessment based upon my day-to-day experiences dealing with this issue up close.