The problem of fulfilling the unlimited wants of humankind with limited or scarce resources. Because of scarcity, economies need to allocate their resources efficiently. Underlying the laws of demand and supply is the concept of utility, which represents the advantage or fulfilment a person receives from consuming a good or service. Utility, then, explains how individuals and economies aim to gain optimal satisfaction in dealing with scarcity.
Utility is an abstract concept rather than a concrete, observable quantity. The units to which we assign an “amount” of utility, therefore, are arbitrary, representing a relative value. Total utility is the aggregate sum of satisfaction or benefit that an individual gains from consuming a given amount of goods or services in an economy. The amount of a person’s total utility corresponds to the person’s level of consumption. Usually, the more the person consumes, the larger his or her total utility will be. Marginal utility is the additional satisfaction, or amount of utility, gained from each extra unit of consumption.
The additional satisfaction a consumer gains from consuming one more unit of a good or service. Marginal utility is an important economic concept because economists use it to determine how much of an item a consumer will buy. The positive marginal utility is when the consumption of an additional item increases the total utility. The negative marginal utility is when the consumption of an additional item decreases the total utility.