Sorry for bumping this ancient thread, but I’m still not quite satisfied with many Austrians’ very strong rejections of cardinal utility as a concept.
I think everyone would agree that there is no way to make interpersonal comparisons of utility, and that there is no way for an outside observer, or even for the actor himself, to put actual numbers on his utility.
Still, doesn’t every decision need some sort of internal (mental) “unit of account” in order to compare the expected psychic benefit of two outcomes and decide which end to aim for? “Ah, but all you need to know is which of the two outcomes you prefer. That is ordinal utility.” you might then respond. But let’s view this from the perspective of the actor. If the actor is selling a bike and one buyer is willing to buy it for 8 carrots and 3 stuffed goats and another is willing to buy it for 5 stuffed goats and 4 carrots. In order to decide which person to sell the bike to, does he not need some way of comparing the utility of consuming carrots to the utility of whatever you can do with stuffed goats? Is it not required to somehow estimate (in your own head) to intensity of “utility” you will experience when eating one carrot, when eating two, three or ten carrots and compare it to the intensity of utility experienced when utilizing a stuffed goat, two stuffed goats, or five?
We need to be able to “lump together” the expected utility of different types of experiences in order to make choices for situations where the different possible outcomes each involve several independed ends, each yielding independent psychic benefits and/or psychic costs. And that includes virtually all decisions we ever make.
We may call this unit of account “intensity of good feelings” or whatever. It is true that no one can put a number on it, no one can measure it and no one can make interpersonal comparisons using it. But the acting individual nevertheless has to use a single scale to compare all different sources of utility, even if he does not understand how he comes to the conclusion that he prefers four stuffed goats and four carrots to a bike, but not three stuffed goats and five carrots.
It is this “unit of account” I think many neoclassical economists tries to symbolize with the letter U in their utility functions. You cannot use it to calculate anything. It is pointless to, as is commonly done in microeconomics and portfolio choice theory, estimate utility functions using numbers and figuring out the optimal amount of inputs to maximize utility. That is pure nonsense. And I agree with Mises that the use of mathematical functions is inappropriate to describe economic/praxeological relationships. Still, that does not necessarily mean that the concept as such is flawed. We could never find out how an individual evaluates the expected utilities of certain ends, but we do know that he does evaluate it and that he must have some sort of unit of account to compare the utilities of different ends.
With that in mind, is it really so unrealistic to use some mathematical equations, which Austrians often raise objections to, such as MU1/P1 = MU2/P2 which simply states (in an economy with only two goods) that an individual will purchase good 1 up until the point where the utility of the last unit of good 1 divided by its price equals to (or is less than, if you object to the psychological state of indifference) the utility of the last good purchased divided by its price?
This does not involve interpersonal comparisons of utility, but it does involve comparisons between the utilities of different ends using a single unit of account (U), namely a comparison between the utility of the consumption of good 1 and the consumption of good 2. If an individual had no single unit of account for utility, wouldn’t his mind then be subject to Mises’ economic calculation problem when making decisions?
These are just some thoughts I had. It is almost 2 am now so what I wrote may not make all that much sense, but I would still really appreciate it if someone could explain where my reasoning went wrong.