Philosophers struggled for centuries to understand the paradox of value, the mystery of why certain luxuries such as diamonds and gold are considered more valuable than certain essentials such as water and food.
Everyone must have water, yet it is usually not that hard to get. We can buy a bottle or it comes out of the tap. Diamonds are rare and expensive, but optional. Men, at least, seem to be able to get along well enough without them. It seems counterintuitive that something essential to everyone’s life could be less valuable than something that seems so much more optional.
Many thinkers tried to understand value as a property of things. They thought that a table, for example, has the property of being flat, having legs, being made of wood, and having a certain value or usefulness. Such approaches are called objective theories of value, because value is seen as a property of the object.
This idea is found in our everyday language when we say that “diamonds are valuable.” But this is also the kind of thinking that produced the paradox of value so it is unlikely to resolve it.
The breakthrough came with two of the greatest ideas in the history of economic thought: the subjective theory of value and the concept of marginal utility. Carl Menger, a professor at the University of Vienna, played a key role in formulating and spreading these two ideas in his 1871 book, Grundsätze der Volkswirtschaftslehre, translated as The Principles of Economics.
Menger is considered the founder of what came to be known as the Austrian School of economics. The name started as a way to distinguish this approach from that of the German Historical School, and the name stuck. Ludwig von Mises, in his 1949 treatise, Human Action, further clarified and extended subjectivism and marginalism, and even insisted that these are among the foundations of any sound economic reasoning.
The subjective revolution clarified that the key to value is valuation. Valuing is an action; it is something that people do. The concept of value makes sense as a relationship between an acting person and the means they select in pursuit of the ends they seek. The object of valuation can be tangible or intangible, base or sublime. It can be anything whatsoever that a person chooses as an end or means as demonstrated in what they actually do. In this view, the value of a thing derives from people valuing it.
Different people have different priorities. The same person has different priorities at different times. A person might buy a bottle of water, but after reading an article on possible risk from plastic bottles, that same person the next day might disvalue and avoid an identical bottle of water. When this same person a year later flies to an anti-plastics conference and crashes in the desert, a plastic bottle of water might suddenly become one of the most valuable things in the universe—to that person, at that time, and in that place.
The marginal revolution built on this insight into the subjectivity of value. No one is actually ever in a position to make a choice between “water in general” and “diamonds in general,” or between all water and all diamonds.
Let’s say I want a drink of water. I go to the kitchen, pour a glass, and drink it. What I chose was not “water in general” but “a glass of water right now.” I didn’t choose two liters of water and I didn’t choose a glass of water tomorrow instead.
This leads to another important concept. If I have one apple, I might just eat it. If I have a second apple, I might give that one to someone else. If I have a third apple, I might keep it for later. In this example, there are three different uses to which I have put each of the three apples.
This has a key implication hiding just below the surface. I showed my priorities with these three uses of each apple. We know this because this is the actual order of uses to which I assigned each additional apple. We know in this example, that I valued eating an apple over giving an apple away because I ate the first apple and gave away the second one. Saving an apple for later was only my third priority for using apples. I only met that priority when I had the third apple and not before. If I had no third apple, my third use for apples would just be left unmet.
So each additional apple I obtained I put to a lower priority use than the apple that came before it. This means that each additional unit of the same good has a lower value to me than that of the unit I used before it. This is the Austrian, or subjectivist, version of what economists call the law of diminishing marginal utility.
All of this has important implications for the idea that value could be measured. To measure distance, we need a unit that is always the same, such as an inch. But with value, things are quite different. In our apple example, each additional apple had a different value than each of the others. Imagine trying to measure a distance if each inch you used was different from every other inch!
The Austrian theory of money and prices builds on this insight. Units of money can be analyzed just like units of apples. Money also has important additional properties and uses, but the theory of money and pricing in the Austrian approach is built on this theory of value and cannot contradict it. It can only elaborate on money as a special case. In other words, money too cannot correctly be described as a measure of value in the same way an inch is a measure of length.
This means that value cannot be measured as we measure things in the natural sciences using length, time, or volume. That kind of measurement uses cardinal numbers such as one, two, and three. What we can use with value is the concept of ranking using ordinal numbers such a first, second, and third. An acting person shows a preference for one thing over another, demonstrates a ranking and ordering of values with every choice and every action.
The dual insights that value is the result of people valuing and that people do not value things in general, but things in particular, resolves the ancient paradox of value. While there were some precursors of these ideas in the history of economic thought, their clear modern formulations originated at the University of Vienna starting in the 1870s and they remain central concepts in the foundations of what is still called the Austrian School of economics today around the world.