The concept of marginal utility refers to the additional satisfaction or benefit that a person derives from consuming an additional unit of a good or service. In other words, it is the incremental benefit that an individual receives from consuming one more unit of a good or service. When it comes to money, the marginal utility of money refers to the additional satisfaction or benefit that a person derives from receiving an additional unit of money.
One of the key assumptions of traditional economic theory is that the marginal utility of money is constant. This means that receiving an additional unit of money will always provide the same level of satisfaction or benefit to an individual, regardless of how much money they already have. According to this theory, a person who has $100 will derive the same level of satisfaction from receiving an additional $1 as a person who has $1,000 will derive from receiving an additional $1.
There are a number of arguments that support the idea of a constant marginal utility of money. One argument is that as a person's wealth increases, they will likely experience a decrease in the intensity of their wants and needs. In other words, as a person's wealth increases, they may become less concerned with acquiring additional material goods and services, and instead may focus more on non-material goals such as personal growth and fulfillment. As a result, the marginal utility of additional units of money may decrease as a person's wealth increases.
Another argument for a constant marginal utility of money is that people have a tendency to adapt to their current level of wealth. This means that as a person's wealth increases, they may become accustomed to their new level of wealth and may no longer feel the same level of satisfaction or benefit from receiving additional units of money. For example, a person who has always lived in poverty may derive a great deal of satisfaction from receiving an additional $100, while a person who is already wealthy may not experience the same level of satisfaction from receiving the same amount of money.
Despite these arguments, there are also several criticisms of the assumption of a constant marginal utility of money. One criticism is that the marginal utility of money is not necessarily constant for all individuals. Different people may have different levels of wealth, different wants and needs, and different levels of satisfaction from receiving additional units of money. As a result, the marginal utility of money may vary significantly from person to person.
Another criticism is that the marginal utility of money may change over time for a single individual. For example, a person who is struggling to meet their basic needs may experience a high marginal utility of money at one point in time, while a person who is already well-off may experience a lower marginal utility of money at the same time.
In conclusion, the concept of a constant marginal utility of money is a key assumption of traditional economic theory. While there are arguments in support of this assumption, there are also criticisms that suggest that the marginal utility of money may vary from person to person and may change over time for a single individual.