The city of Greensboro, N.C., has experimented with a program designed for teenage mothers. To prevent these teens from having another child, the city offered each of them $1 a day for every day they were not pregnant. It turns out that the psychological power of that small daily payment is huge. A single dollar a day was enough to push the rate of teen pregnancy down, saving all the incredible costs — human and financial — that go with teen parenting.
via npr.org
Behavioral economics and psychology is damn interesting.