Preferensism is a combination of Social Choice and Utilitarianism. Both fields present difficulties for building a societal architecture. First, according to Nobel Laureate Kenneth Arrow, Social Choice is impossible. See Arrow's Impossibility Theorem. That is the amalgamation of individual preference profiles in order to form an overall social decision is impossible. Well, all I can say to that is "The difficult we can do right away; the impossible will take a little longer." We have dealt with a number of ways around this difficulty both in this blog and in Social Choice and Beyond. Probably the biggest difficulty, before the advent of high speed computers and voluminous hard drives, was just dealing with the overwhelming amount of data that would be generated. This shouldn't be a problem in the 21st Century.
Utilitarianism was developed by 19th century English philosophers such as Jeremy Bentham and John Stuart Mill. That's him in the picture. Their slogan was "the greatest good for the greatest number." This too has come in for a lot of criticism by folks who say "you can't maximize two dependent variables simultaneously." This may be literally true. However, as I have pointed out, you can maximize "the greatest good" and, subject to that condition, if there are a number of tied ways to do this, you can choose the one that minimizes some measure of inequality. So all is not lost.
If we assume for a minute that Social Choice is possible and Utilitarianism is not oxymoronish, we can see that it is necessary to choose what type of Social Choice function, out of the many available, we want to implement. That's where Utilitarianism comes in. It gives us the moral and ethical guidance we need in order to choose one Social Choice function. Essentially what we want to do in Preferensism is to allow each individual citizen one vote consisting of a list of preferences. The individual's utility or happiness or satisfaction depends on which preference the individual ends up getting as assigned by the Social Choice function. Without loss of generality, we can assume that the individual gets a maximum utility of 1 if he gets his first choice and 0 if he gets his last choice. If he gets assigned a preference somewhere between his first and last, he would have a utility somewhere between 0 and 1.
Now of all the ways that the Social Choice function, also known as the Social Decision Function (SDF), could assign individual outcomes such that the overall social outcome makes sense, we can compute the overall utility or satisfaction of the whole society by adding up all the individual utilities or satisfactions. Then we can choose the SDF that maximizes social utility. Assuming that there are a number of tied solutions or a number of different ways of doing this, we can choose the one that minimizes inequality where inequality is defined as the sum of the differences between the average utility and the individual utilities.
Therefore, we have created a method which combines social choice and utilitarianism in such a way as to combine individual inputs, treating each in an equal manner, to produce a social solution which maximizes social satisfaction or utility and, subject to that condition, minimizes social inequality.
The individual preference profiles could be either political or economic in nature. They could be a list of candidates standing for election or they could be a list of work-consumption bundles. That is each entry might represent the amount of work the individual is willing to do in return for the corresponding bundle of consumer items. On the one hand the social outcome (such as the election of a President) could apply to every individual; on the other hand the social outcome could assign a different work-consumption bundle to each individual.
