Shortage is the fundamental economic problem of having virtually infinite human desires in a world of limited resources. He postulates that society has insufficient means of production and resources to meet the desires and needs of all human beings. One misconception about scarcity is that an item has to be important to be considered scarce. However, this is not true, since for something to be scarce it must be difficult to obtain, to produce, or both. In short, the cost of producing a good determines whether it is scarce or not. For example, although the air we breathe is more important than diamonds, it is cheaper to obtain precisely because it is abundant and has zero production cost. Diamonds, on the other hand, have a very high cost of production; they need to be found and stoned, and both processes cost dearly. In addition, the Scarcity Act implies that not all of society's goals and needs can be met at the same time; choices and decisions are necessary for one good to the detriment of others.
The resource must be finite to be scarce. The resource must be hard to obtain. Society must lack the capability of producing the resource for all the population. So, for a product to be scarce is has to be finite, costly to obtain or produce and there must be an interest in consuming those products.