Actually, many of the homeless actually prefer to be homeless. When given opportunity, they usually end up back on the streets. In some ways, they do not want to live in our world. It is just a hard concept for us to get our heads around, because if we were homeless we would prefer to live somewhere. Many Katrina victims actually did live somewhere and were happy to have shelter.
An interesting read is “The Glass Castle.” And, a somewhat disturbing movie is “Wendy and Lucy.”