Economics is the study of scarcity. Scarcity exists because the society has unlimited needs and wants but the resources to satisfy these are unfortunately, not unlimited. That is why there is a certain cost to scarce things. The scarcer the thing is, the more its costs. Aside from scarcity, factors like production cost and capital affect the cost of a thing, commonly referred to as a good.
I believe you have to write up your own. I hope this comes in handy^-^
