An anonymous reader writes: If someone is about to become homeless, giving them a single cash infusion, averaging about $1000, may be enough to keep them off the streets for at least 2 years. That's the conclusion of a new study, which finds that programs that proactively assist those in need don't just help the victims -- they may benefit society as a whole. "I think this is a really important study, and it's really well done," says Beth Shinn, a community psychologist at Vanderbilt University in Nashville who specializes in homelessness but was not involved in the work. Homelessness isn't just bad for its sufferers -- it shortens life span and hurts kids in school -- it's a burden on everyone else. Previous studies have concluded that a single period of homelessness can cost taxpayers $20,000 or more, in the form of welfare, policing, health care, maintaining homeless shelters, and other expenses. To combat homelessness, philanthropic organizations have either tried to prevent people from losing their homes in the first place or help them regain housing after they are already destitute. But there aren't many data on whether giving cash to people on the brink of becoming homeless actually prevents them from living on the street.