peace
Yes, it is very important to teach the youth economics and i've tried to instill this into my son since he was around 5 or 6. I would send him into the store by himself and i would stand outside and watch from the window. I'd give him some money for what he wanted and in order to be able to get it, he'd have to tell me how much change he should receive back and to not just stuff whatever they give him back in his little pockets without counting it right in front of them. Imagine a 6 year old on line by himself in dunken doughnuts ordering a couple of doughnuts with no adult in sight. I'd be right outside the door watching the other adults on line looking at him order and pay for his own meal and they would laugh with surprise. Then, as he'd start walking toward the door they would see me there smiling and some would nod....
This is how i was first taught. My moms was like, "if you don't know how much you're supposed to get back, then you don't need what you think you want in the first place because everybody doesn't play fair...."
It might sound crazy, but again, i repeat that with a knowledge of self instilled into our children learning economics will be easy and almost natural for them to curb their spending and learn to spend with their own.