The homeless and the unemployed are already a financial drain on society, receiving welfare and other assistance from taxpayer money. Once they have essentially gone on the dole and become a burden on society they have essentially become endebted to society. Wouldn't it be better to offer a different route, where they can be productive and useful and live a decent life, and get some preparation to move back into society and carry their fair share of responsibility?
My only concern with a program like this is that I think some participants will become dependent on the system, especially on the imposed structure of the lifestyle, and be unwilling to ever leave it. There's also the issue of permanent participants and old age. The system might not be able to accomodate those who cannot work well, though some sort of semi-retirement element could be built into it.
There's more to be worked out, but it is something to muse on.
Henderson, Davis et al. The Life and Economics of David Ricardo
Dickens, Charles, A Christmas Carol
Dickens, Charles, Oliver Twist
Wood, Peter, Poverty and the Workhouse in Victorian Britain