Harry Potter's economics
Criticized here.
She's got some good points. Rowling's wizard economic system doesn't hang together very well. It's implied that there are serious laws against, for example, making gold, but other things are routinely pulled out of thin air. Money is used all the time for routine purchases. Nobody ever sees a student refilling his glass of butterbeer by waving a wand at it, although this shouldn't be hard.
In Star Trek, "gold-pressed latinum" (whatever the hell that actually is) is assumed to be worth something because for some reason it can't be replicated.