Jeremy Bentham’s utility is a hypothetical unit of morality used as the underpinning for modern economic modelling using a cardinal quantitative approach. One problem is that economics has abused his concept.
Today, many economists treat utility as a unit of happiness. This is due to the need for two separate concerns, both of which rely on math coming from the rational actor model which employs the idea of utility.
Indeed some economists have gone in the direction of radically behavioral economics and looking at the very chemical fluctuations in brains which signal happiness as some signal of utility or preference. While this was definitely worth study, this idea is completely outside the original Benthamian scope.
Bentham’s utility is not merely a Friedmanian predictive tool. It is a moral defense of the ability of economists to say, “We should do X, not Y.” Utilitizing Bentham’s framework is a way to morally support efficiency as objectively preferable. We can also take the pragmatic approach, and it turns out to coincide as well which is interesting itself.
Anyway we have two or three seperate concerns which we should discuss separately, not conflating the same term of ‘utility’ to describe:
- The concern about what is really morally optimal for some person to do (the concern of Bentham the philosopher).
- The concern about what is probable or likely that some person is going to do (the concern of the rational actor model, and perhaps most modern economists).
- The concern about what is happiness and what is going to make some person or society most happy. This is related to concerns Kahnemen and other psychologists and so on have, but it was original an economic interest in service of simply modelling what some person would do under the theory they would pursue happiness.
More on this later as once we separate these concerns a whole other project is modelling their intricate interrelations. These concepts are neither synonymous nor independent.