" 'We know that people in the short term have a lot of trouble changing their behavior in ways that is in their long-term best interest,' says Kevin Volpp, Wharton professor of medicine and health care management, and a professor at the University of Pennsylvania School of Medicine. 'People aren't very good at making these tradeoffs between immediate gratification and delayed and often intangible benefits, such as good health 10 years from now.' Volpp -- with collaborators ... -- may have found an answer to this problem: cash."  MORE >>