Teenagers in Iceland in the 80's and 90's were out of control. It was a huge problem and in 1998, some 42% of them said they had got drunk. But, now it's only 5%.
Here's how they did it: (For details, please watch the video below)
1. Bring in a curfew
Kids under 16 must be indoor by 10 pm, so some parents go on patrol.
2. Parents sign a pledge
Groups of parents agree on rules for their children's behaviour.
3. Keep kids occupied
Every year they get a $500 voucher for after-school activities.
4. Base it all on science
Teenagers fill in a survey every year
5. Get the politicians onside
You have to decide to build what you do on evidence and research