What Is the Difference Between Marginal Utility and Marginal Value?

Depending on the context, marginal utility and marginal value can describe the same thing. The key word for each is “marginal;” that is, the incremental change based on the per-unit shift in a good or service. This may sound complicated, but it really is not. Once you understand the meaning behind the related economic concepts, it is easy to see the differences between the two terms.

Understanding Marginalism

Marginalism was first formulated into a formal theory in the 1870s, when economists suggested that human beings make decisions “on the margin.”

For example, marginalism explains the differences in the value of goods and services by considering their marginal utility. iPhones are more expensive than water, for example, because iPhones bring greater satisfaction to whoever possesses them. Although water has greater total utility—it is necessary to sustain life—the iPhone has greater marginal utility

This helps explain why one additional unit of water is rarely as valuable as one additional iPhone, even though water is necessary for life, and iPhones are unnecessary consumer goods. Thus, when a business owner or individual makes an economic decision, they do so marginally, based on how valuable one extra unit of that item is to them at a specific point in time.

Marginal Utility and Marginal Value

Utility is the economic term for satisfaction. A basic economic insight is human beings act purposefully to satisfy wants or to remove discomfort. The more utility an item has, the more value human beings are willing to assign to it. In this way, utility can be synonymous with subjective human value.

Another way to think of marginal utility and value is to imagine that you are deciding how many apples to consume. Presumably, you would prefer to have one apple to having none. If the only alternative was to have 21 apples a week or 20, you might still want the extra apple, but it would not be worth as much to you as having that first apple. So, marginal utility decreases as the quantity of apples increases, and, at some point, you do not want any more apples, and the marginal utility of another apple is zero.

Marginal value is what one more unit of a good— the apple—is worth to you in terms of other goods. Unlike marginal utility, it is in principle because it is difficult to measure how much value different individuals place on items, or the value of one more of that item.

Marginal Value Is Not Market Value

However, utility is not the same thing as market value, which is expressed in dollars. Utility is personal: what has utility for one person might not have the same utility for another. A keen cyclist might assign a high level of utility to a new bicycle, whereas a runner would assign more utility to a pair of running shoes. Market value, on the other hand, is aggregated and impersonal.

For example, if a toy company increases its marginal value by boosting its economies of scale, this has nothing to do with an individual’s marginal utility. Here, marginal value just means an incremental increase in market value.