For a Total Utilitarian it’s not a problem to be missing a zero point (unless you’re talking about adding/removing people).
For an Average Utilitarian, or a Total Utilitarian considering birth or death, you try to identify the point at which a life is not worth living. You estimate as well as you can.
Doesn’t “multiplication by a constant” mean births and deaths? Which puts you in my second paragraph: you try to figure out at what point it would be better to never have lived at all. The point at which a life is a net negative is not very clear, and many Utilitarians disagree on where it is. I agree that this is a “big problem”, though I think I would prefer the phrasing “open question”.
Asking people to trade off various goods against risk of death allows you to elicit a utility function with a zero point, where death has zero utility. But such a utility function is only determined up to multiplication by a positive constant. With just this information, we can’t even decide how to distribute goods among a population consisting of two people. Depending on how we scale their utility functions, one of them could be a utility monster. If you choose two calibration points for utility functions (say, death and some other outcome O), then you can make interpersonal comparisons of utility — although this comes at the cost of deciding a priori that one person’s death is as good as another’s, and one person’s outcome O is as good as another’s, ceteris paribus, independently of their preferences.
We can’t “just add these [preferences] up across people equally” because utility functions are only defined up to an affine transformation.
You might be able to “just add up” pleasure, on the other hand, though you are then vulnerable to utility monsters, etc.
For a Total Utilitarian it’s not a problem to be missing a zero point (unless you’re talking about adding/removing people).
For an Average Utilitarian, or a Total Utilitarian considering birth or death, you try to identify the point at which a life is not worth living. You estimate as well as you can.
Multiplication by a constant is an affine transformation. This clearly is a very big problem.
But all we want is an ordering of choices, and affine transformations (with a positive multiplicative constant) are order preserving.
Doesn’t “multiplication by a constant” mean births and deaths? Which puts you in my second paragraph: you try to figure out at what point it would be better to never have lived at all. The point at which a life is a net negative is not very clear, and many Utilitarians disagree on where it is. I agree that this is a “big problem”, though I think I would prefer the phrasing “open question”.
Asking people to trade off various goods against risk of death allows you to elicit a utility function with a zero point, where death has zero utility. But such a utility function is only determined up to multiplication by a positive constant. With just this information, we can’t even decide how to distribute goods among a population consisting of two people. Depending on how we scale their utility functions, one of them could be a utility monster. If you choose two calibration points for utility functions (say, death and some other outcome O), then you can make interpersonal comparisons of utility — although this comes at the cost of deciding a priori that one person’s death is as good as another’s, and one person’s outcome O is as good as another’s, ceteris paribus, independently of their preferences.
Yes, thank you for taking the time to explain.