I'm 17 now. And I started to work officially when I was 16.
I'm generating income from 14 years old. I'm web programmer.
So I think it is very good when you start generating incomes when you are young, because you don't have to care your living, you can learn how to manage your money, how to invest it and so on.
Every human must know how to manage his / her money. So If person started early, it would be very good