"A chronically homeless person costs the tax payer an average of $35,578 per year. Costs on average are reduced by 49.5% when they are placed in supportive housing. Supportive housing costs on average $12,800, making the net savings roughly $4,800 per year."
This has been known for a long time. It costs the public less to provide direct federal and state-financed housing for the homeless than to keep them on the streets. Finland and many other countries do this and they have the happiest people in the world. States like Utah have also implemented successful programs based on this model. The question isn't what do we do, it's why aren't we doing what we know works.