What externalities does the issue raise?

Some of the externalities is that these people will probably always be homeless because it will be very hard for them to get a job. Also many people are homeless so they think that if they do something bad then they can go to jail where they would at least have a bed, food, and medical care for free. So if people just help out homeless people in the first place then we would be saving our money and not have to pay for them to basically live a pretty decent life in jail.