Law Of Diminishing Marginal Utility

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What is the 'Law Of Diminishing Marginal Utility'

The law of diminishing marginal utility is a law of economics stating that as a person increases consumption of a product while keeping consumption of other products constant, there is a decline in the marginal utility that person derives from consuming each additional unit of that product. Marginal utility is derived as the change in utility as an additional unit is consumed.

BREAKING DOWN 'Law Of Diminishing Marginal Utility'

Marginal utility may decrease into negative utility, as it may become entirely unfavorable to consume another unit of any product. Therefore, the first unit of consumption for any product is typically highest, with every unit of consumption to follow holding less and less utility. Consumers handle the law of diminishing marginal utility by consuming numerous quantities of numerous goods.

Diminishing Prices

The law of diminishing marginal utility directly relates to the concept of diminishing prices. As the utility of a product decreases as its consumption increases, consumers are willing to pay smaller dollar amounts for more of the product. For example, assume an individual pays $100 for a vacuum cleaner. Because he has little value for a second vacuum cleaner, the same individual is willing to pay only $20 for a second vacuum cleaner. The law of diminishing marginal utility directly impacts a company’s pricing because the price charged for an item must correspond to the consumer’s marginal utility and willingness to consume or utilize the good.

Example of Diminishing Marginal Utility

An individual can purchase a slice of pizza for $2; she is quite hungry and decides to buy five slices of pizza. After doing so, the individual consumes the first slice of pizza and gains a certain positive utility from eating the food. Because the individual was hungry and this is the first food she consumed, the first slice of pizza has a high benefit. Upon consuming the second slice of pizza, the individual’s appetite is becoming satisfied. She wasn't as hungry as before, so the second slice of pizza had a smaller benefit and enjoyment as the first. The third slice, as before, holds even less utility as the individual is now not hungry anymore.

In fact, the fourth slice of pizza has experienced a diminished marginal utility as well, as it is difficult to be consumed because the individual experiences discomfort upon being full from food. Finally, the fifth slice of pizza cannot even be consumed. The individual is so full from the first four slices that consuming the last slice of pizza results in negative utility. The five slices of pizza demonstrate the decreasing utility that is experienced upon the consumption of any good. In a business application, a company may benefit from having three accountants on its staff. However, if there is no need for another accountant, hiring a fourth accountant results in a diminished utility, as little benefit is gained from the new hire.