Neoclassical economics is fundamentally flawed. Hulsmann writes: "In short, neoclassical value theory not only stresses that what we feel determines how we behave. It presupposes that there are constant relationships between our feelings on the one hand, and our behavior on the other hand that can be studied and described by the neoclassical consumer theory. Such are the problems that monopolize the attention of neoclassical economists. Their efforts and ingenuity have brought us a huge literature on game theory, on maximization problems in different market settings, on equilibrium paths, etc.
However, all of this literature is based on the wrong premise that there are constant relationships between the conditions of action and action itself. The truth is that there are no laws governing which things people choose and which ends they pursue."
Mises adds: "The econometrician is unable to disprove this fact, which cuts the ground from under his reasoning. He cannot help admitting that there are no 'behavior constants.' Nonetheless he wants to introduce some numbers, arbitrarily chosen on the basis of a historical fact, as 'unknown behavior constants.' The sole excuse he advances is that his hypotheses are 'saying only that these unknown numbers remain reasonably constant through a period of years.' Now whether such a period of supposed constancy of a definite number is still lasting or whether a change in the number has already occurred can only be established later on. In retrospect it may be possible, although in rare cases only, to declare that over a (probably rather short) period an approximately stable ratio--which the econometrician chooses to call a 'reasonably' constant ratio-prevailed between the numerical values of two factors. But this is something fundamentally different from the constants of physics. It is the assertion of a historical fact, not of a constant that can be resorted to in attempts to predict future events."
In short, there is also supposedly a constant relationship between utility and actions (or even prices and actions). Yet, there is no such thing as a "util" (sort of a common denominator of preferred actions, means and ends), thus interpersonal utility comparisons are impossible. This is the proverbial carpet yanked out from under the neoclassicists by Austrian economics. But, while these fundamental issues are rarely discussed, I contend they are being pursued as we speak through the field of neuroeconomics! If neuroeconomics can discover "constants" of human behavior, ie some biological process which produces a certain human action, will neoclassical economics reaffirm its foundations? In other words, will the neuroeconomists be able to explain observable behavior (actions) through observable phenomenon (brain waves)?