Thought-provoking indeed. I agree with you that the scale we’ve picked for utils is arbitrary, and the zero we’ve picked is also arbitrary. After reading through the comments, I begin to wonder if we should go farther. We talk about utils as if this is a quantity we can actually measure, but is that true? Are we measuring anything at all? Is a numeric measure of any kind at all helpful here?
Let me propose a situation: Given a choice between beer and steak, John chooses the steak. Given a choice between steak and ice cream, John chooses the ice cream. Given a choice between ice cream and beer, John chooses the beer. Which item has the highest utility to John? There’s just no way to make sense of that in terms of real-valued utils because real numbers are transitive, and utility doesn’t have to be.
If utils do make sense, I ask someone to produce an actual means of measuring them, fuzzy and approximate thought it may be. I can’t figure out any mathematically consistent way to do this that doesn’t resolve to some other more easily measured quantity such as money or dopamine levels or quality-adjusted life years (QALYs). And if one of those is what we’re measuring, then we should probably just go ahead and say so.
In fact, in different problems we’re likely to want different kinds of utility. Sometimes a problem is best understood in terms of money. In others, it’s better understood in QALYs, and money may be not the measure but rather the constraint. That is, given that we have X dollars to work with, how can we maximize QALYs?
Bu if we just use abstract “utils” or “utilons” without connecting those to something we can measure in the non-hypothetical world, I’m not sure we get any useful information that applies outside of an axiomatic system that may not model reality.
Given a choice between beer and steak, John chooses the steak. Given a choice between steak and ice cream, John chooses the ice cream. Given a choice between ice cream and beer, John chooses the beer.
Does this really happen? Can money be pumped out? For example, offer John the opportunity to pay $0.05 to upgrade his beer for a steak, then $0.05 to upgrade that to an ice cream cone, then $0.05 to upgrade that to a beer. Run forever. I think if you actually did this you’d find that of the three there actually is one that John would prefer to have.
Yes, real human preference is routinely intransitive. That’s a topic perhaps worth its own discussion.
The parent post is still relevant, though. Inasmuch as utilitarian calculations are a useful approximation to human decisionmaking, it’s worth reminding people here that utilities don’t have a natural magnitude scale and that there’s no natural way to compare them across agents.
Thought-provoking indeed. I agree with you that the scale we’ve picked for utils is arbitrary, and the zero we’ve picked is also arbitrary. After reading through the comments, I begin to wonder if we should go farther. We talk about utils as if this is a quantity we can actually measure, but is that true? Are we measuring anything at all? Is a numeric measure of any kind at all helpful here?
Let me propose a situation: Given a choice between beer and steak, John chooses the steak. Given a choice between steak and ice cream, John chooses the ice cream. Given a choice between ice cream and beer, John chooses the beer. Which item has the highest utility to John? There’s just no way to make sense of that in terms of real-valued utils because real numbers are transitive, and utility doesn’t have to be.
If utils do make sense, I ask someone to produce an actual means of measuring them, fuzzy and approximate thought it may be. I can’t figure out any mathematically consistent way to do this that doesn’t resolve to some other more easily measured quantity such as money or dopamine levels or quality-adjusted life years (QALYs). And if one of those is what we’re measuring, then we should probably just go ahead and say so.
In fact, in different problems we’re likely to want different kinds of utility. Sometimes a problem is best understood in terms of money. In others, it’s better understood in QALYs, and money may be not the measure but rather the constraint. That is, given that we have X dollars to work with, how can we maximize QALYs?
Bu if we just use abstract “utils” or “utilons” without connecting those to something we can measure in the non-hypothetical world, I’m not sure we get any useful information that applies outside of an axiomatic system that may not model reality.
Does this really happen? Can money be pumped out? For example, offer John the opportunity to pay $0.05 to upgrade his beer for a steak, then $0.05 to upgrade that to an ice cream cone, then $0.05 to upgrade that to a beer. Run forever. I think if you actually did this you’d find that of the three there actually is one that John would prefer to have.
Yes, real human preference is routinely intransitive. That’s a topic perhaps worth its own discussion.
The parent post is still relevant, though. Inasmuch as utilitarian calculations are a useful approximation to human decisionmaking, it’s worth reminding people here that utilities don’t have a natural magnitude scale and that there’s no natural way to compare them across agents.