The Fighting Mongoose

Philosophy, n. A route of many roads leading from nowhere to nothing. -Ambrose Bierce
A group weblog by the graduate philosophy students at the University of Wisconsin-Milwaukee

Monday, September 04, 2006

Within utilitarianism, there has been a classic debate between total and average utility. This distinction comes into play when there are questions of population size being discussed. If we were deciding as good utilitarians whether or not to fund greater access to birth control we may have to consider whether it is better to have a larger population or not. Given that birth control policy may not produce very precise results, we can assume that you have two options.

The first option is to not fund birth control and to restrict its access, such as by making the morning after pill require a prescription which would delay access, in order to allow the population to grow. This will result in having a very high population, and the population density may limit the joy everyone feels. As long as people are on average experiencing positive utility, this may be the best way to maximize the total level of happiness.

Some theorists believe that this is a bad outcome and that a smaller society of people happy with resource abundance would be preferred to a large society where scarcity prevents flourishing and the experiencing of greater degrees of average utility.

Population :: Average Utility :: Total Utility

1,000,000 :: 2 utils/person :: 2,000,000 utils

100,000 :: 8 utils/person :: 800,000 utils

In this chart, the average person in the smaller population are experiencing four times as much happiness, or happiness four times as often, than the average individual from the high population world. One may think that the smaller population is better off, and therefore exemplifies the “greatest good” desired by utilitarians. The greatest average utility principle may give very bad results in other situations however, and I will review one result which may be intuitively bad.

Having decided to spread birth control through your society and have a small and joyous populous, you now have a new decision to make. There is a group in your society the members of which are happy (say averaging 1 utils), but not as happy as the average for your society. This group is fairly isolated, so no one would miss them or be missing out on their production if the group were to disappear. You have the ability to make this group disappear and, though this would be eliminating happy people, this will increase the average happiness of the society. This creates a decision chart like:

Population :: Average Utility

100,000 :: 8

90,000 :: 8.7

Thus, if you just killed this group you would maximize average utility just as you did by encouraging birth control.

One man’s modus tollens is another man’s modus ponens.


At 9:38 PM, Blogger James Lee said...

Hey Chad,

Correct me if I'm wrong, but isn't the classic notion of the greatest good, i.e. the notion promoted by Bentham and Mill, the notion of total utility, which you mention above?

As you argue, the notion of average utility (AU) seems to result in utilitarianism ultimately collapsing into a form of egoism. We could imagine an insane despot who would gain 10,000 utils if he killed everyone else, thus netting an average utility of 10,000 utils/person. In this case, AU utilitarianism would have to concede that the despot should act in his own self-interest.

How would an AU utilitarian respond to such a scenario?

At 1:14 PM, Blogger Mark Arciaga said...

I don't have much experience in utilitarianism, but it seems to me that this scenario exposes the flaws in cashing out moral worth in terms of some type of calculus. Quite counterintuitive.

At 10:27 PM, Blogger anti-Chalmers said...

I've always wondered what exactly a unit of happiness was s'posed to correspond to in the world. It seems that no one ever likes to ask this question, probably because of the paucity of options. I suspect there is no satisfying answer. Note that this affects not only utilitarian analyses of the type that Chad utilizes, but also various areas of philosophy and even areas of academia wch appeal to generic units of utility, such as economics.

At 11:52 PM, Blogger Chad Van Schoelandt said...

"what exactly a unit of happiness was s'posed to correspond to in the world"

Best guess is that they are a quick reference to expected subjective preferences. So I like drinking green tea with honey more than just green tea, but not a lot more. I like drinking green tea way more than prune juice. If we played this game enough we would begin to get rough numbers to represent my preferences. Economics does this with money.

At 4:18 AM, Anonymous Richard said...

I'm sympathetic to an Average Utility view according to which value is atemporal. Killing someone doesn't remove their life from the calculus. Their past existence cannot be erased. All that killing someone does is (in most cases) make their life go worse than it otherwise would have. So in fact my version of AU gives the intuitively correct result in the "insane despot" case.

At 2:57 AM, Blogger Genius said...

the total utiity perspective has it's own controls.

The main threats to long term utility would be things like
1) Some sort of stupid behaviour as a result of stress (eg a big war)
2) key resources being consumed faster than they can be replaced.
3) etc etc

thus keeping the results reasonably sensible.

For example related to (2) above - one would have to introduce controls when one was running down a key resource and yet at that point one would probably still have a lot of utility left.

Besides - IF there was a certain amount of utility to go around it would be reasonably to extend the consumption of that utility over ones other resources (such as time and space) resulting in no overpopulation.


Post a Comment

<< Home