= 27d567bc2d48d9f40e9ccc20ea370b15)
PhilGoetz comments on Average utilitarianism must be correct? - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (159)
As is well known, I have a poor model of Eliezer.
<EDIT> (I realize Eliezer is familiar with the problems with taking average utility; I write this for those following the conversation.) </EDIT>
So, if we are to choose between supporting a population of 1,000,000 people with a utility of 10, or 1 person with a utility of 11, we should choose the latter? If someone's children are going to be born into below-average circumstances, it would be better for us to prevent them from having children?
(I know that you spoke of all living people; but we need a definition of rationality that addresses changes in population.)
Inequitable distributions of utility are as good as equitable distributions of utility? You have no preference between 1 person with a utility of 100, and 9 people with utilities of 0, versus 10 people with utilities of 10? (Do not invoke economics to claim that inequitable distributions of utility are necessary for productivity. This has nothing to do with that.)
Ursula LeGuin wrote a short story about this, called "The ones who walk away from Omelas", which won the Hugo in 1974. (I'm not endorsing it; merely noting it.)
The reason why an inequitable distribution of money is problematic is that money has diminishing marginal utility; so if a millionaire gives $1000 to a poor person, the poor person gains more than the millionaire loses.
If your instincts are telling you that an inequitable distribution of utility is bad, are you sure you're not falling into the "diminishing marginal utility of utility" error that people have been empirically shown to exhibit? (can't find link now, sorry, I saw it here).
That's why I said "utility" instead of "money".
Er, I know, I'm contrasting money and utility. Could you expand a little more on what you're trying to say about my point?
The term "utility" means that I'm taking diminishing marginal returns into account.
My instincts are confused on the point, but my impression is that most people find average utilitarianism reprehensible.
Perhaps it would help if you gave a specific example of an action that (a) follows from average utilitarianism as you understand it, and (b) you believe most people would find reprehensible?
The standard answer is killing a person with below-average well-being*, assuming no further consequences follow from this. This assumes dying has zero disutility, however.
See comments on For The People Who Are Still Alive for lots of related discussion.
*The term "experienced utility" seems to be producing a lot of confusion. Utility is a decision-theoretic construction only. Humans, as is, don't have utility functions.
It also involves maximizing average instantaneous welfare, rather than the average of whole-life satisfaction.
Yes, I'm surprised that it's average rather than total utility is being measured. All other things being equal, twice as many people is twice as good to me.
You don't interpret "utility" the same way others here do, just like the word "happiness". Our utility inherently includes terms for things like inequity. What you are using the word "utility" here for would be better described as "happiness".
Since your title said "maximizing expected utility is wrong" I assumed that the term "average" was to be taken in the sense of "average over probabilities", but yes, in a Big and possibly Infinite World I tend toward average utilitarianism.
We had the happiness discussion already. I'm using the same utility-happiness distinction now as then.
(You're doing that "speaking for everyone" thing again. Also, what you would call "speaking for me", and misinterpreting me. But that's okay. I expect that to happen in conversations.)
<EDITED TO USE STANDARD TERMINOLOGY>
The little-u u(situation) can include terms for inequity. The big-U U(lottery of situations) can't, if you're an expected utility maximizer. You are constrained to aggregate over different outcomes by averaging.
Since the von Neumann-Morgenstern theorem indicates that averaging is necessary in order to avoid violating their reasonable-seeming axioms of utility, my question is then whether it is inconsistent to use expected utility over possible outcomes, and NOT use expected utility across people.
Since you do both, that's perfectly consistent. The question is whether anything else makes sense in light of the von Neumann-Morgenstern theorem. </EDIT>
<part below left as is because someone responded to it> If you maximize expected utility, that means that an action that results in utility 101 for one future you in one possible world, and utility 0 for 9 future yous in 9 equally-likely possible worlds; is preferable to an action that results in utility 10 for all 10 future yous. That is very similar to saying that you would rather give utilty 101 to 1 person and utility 0 to 9 other people, than utility 10 to 10 people.
I disagree: that's only the case if you have perfect knowledge.
Case A: I'm wondering whether to flip the switch of my machine. The machine causes a chrono-synclastic infundibulum, which is a physical phenomenon that has a 50% chance of causing a lot of awesomeness (+100 utility), and a 50% chance of blowing up my town (-50 utility).
Case B: I'm wondering whether to flip the switch of my machine, a friendly AI I just programmed. I don't know whether I programmed it right, if I did it will bring forth an awesome future (+100 utility), if I didn't it will try to enslave mankind (-50 utility). I estimate that my program has 50% chances of being right.
Both cases are different, and if you have a utility function that's defined over all possible future words (that just takes the average), you could say that flipping the switch in the first case has utility of +50, and in the second case, expected utility of +50 (actually, utility of +100 or -50, but you don't know which).
This doesn't sound right to me. Assuming "world" means "world at time t", a utility function at the very least has type (World -> Utilons). It maps a single world to a single utility measure, but it's still defined over all worlds, the same way that (+3) is defined over all integers. If it was only defined for a single world it wouldn't really be much of a function, it'd be a constant.
We use expected utility due to uncertainty. If we had perfect information, we could maximize utility by searching over all action sequences, computing utility for each resulting world, and returning the sequence with the highest total utility.
I think this illustrates the problem with your definition. The utility you're maximizing is not the same as the "utility 101 for one future you". You first have to map future you's utility to just plain utility for any of this to make sense.
I meant "the domain of a utility function is a single world."
However, it turns out that the standard terminology includes both utility functions over a single world ("outcome"), and a big utility function over all possible worlds ("lottery").
My question/observation is still the same as it was, but my misuse of the terminology has mangled this whole thread.
Phil, this is something eerie, totally different from the standard von Neumann-Morgenstern expected utility over the world histories, which is what people usually refer to when talking about the ideal view on the expected utility maximization. Why do you construct this particular preference order? What do you answer to the standard view?
I don't understand the question. Did I define a preference order? I thought I was just pointing out an unspoken assumption. What is the difference between what I have described as maximizing expected utility, and the standard view?
The following passage is very strange, it shows either lack of understanding, or some twisted terminology.
It shows twisted terminology. I rewrote the main post to try to fix it.
I'd like to delete the whole post in shame, but I'm still confused as to whether we can be expected utility maximizers without being average utilitarianists.
I've thought about this a bit more, and I'm back to the intuition that you're mixing up different concepts of "utility" somewhere, but I can't make that notion any more precise. You seem to be suggesting that certain seemingly plausible preferences cannot be properly expressed as utility functions. Can you give a stripped-down, "single-player" example of this that doesn't involve other people or selves?
Here's a restatement:
If you want a more equitable distribution of utility among future selves, then your utility function u(outcome) may be a different function than you thought it was; e.g. the log of the function you thought it was.
More generally, if u is the function that you thought was your utility function, and f is any monotonically increasing function on the reals with f'' < 0, then by Jensen's inequality, an expected f''(u)-maximizer would prefer to distribute u-utility equitably among its future selves.
Nope. You can have u(10 people alive) = -10 and u(only 1 person is alive)=100 or u(1 person is OK and another suffers)=100 and u(2 people are OK)=-10.
I'm with you so far.
What do you mean by "distribute utility to your future selves"? You can value certain circumstances involving future selves higher than others, but when you speak of "their utility" you're talking about a completely different thing than the term u in your current calculation. u already completely accounts for how much they value their situation and how much you care whether or not they value it.
I don't see how this at all makes the case for adopting average utilitarianism as a value framework, but I think I'm missing the connection you're trying to draw.
I'd hate to see it go. I think you've raised a really interesting point, despite not communicating it clearly (not that I can probably even verbalize it yet). Once I got your drift it confused the hell out of me, in a good way.
Assuming I'm correct that it was basically unrelated, I think your previous talk of "happiness vs utility" might have primed a few folks to assume the worst here.
If you don't prefer 10% chance of 101 utilons to 100% chance of 10, then you can rescale your utility function (in a non-affine manner). I bet you're thinking of 101 as "barely more than 10 times as much" of something that faces diminishing returns. Such diminishing returns should already be accounted for in your utility function.
No. I've explained this in several of the other comments. That's why I used the term "utility function", to indicate that diminishing returns are already taken into account.
Phil, you're making a claim that what others say about utility (i.e. that it's good to maximize its expectation) is wrong. But it's only on your idiosyncratic definition of utility that your argument has any traction.
You are free to use words any way you want (even if I personally find your usage frustrating at times). But you are not free to redefine others' terms to generate an artificial problem that isn't really there.
The injunction to "maximize expected utility" is entirely capable of incorporating your concerns. It can be "inequality-averse" if you want, simply by making it a concave function of experienced utility.
No. I've said this 3 times already, including in the very comment that you are replying to. The utility function is not defined across all possible outcomes. A utility function is defined over a single outcome; it evaluates a single outcome. It can discount inequalities within that outcome. It cannot discount across possible worlds. If it operated across all possible worlds, all you would say is "maximize utility". The fact that you use the word "expected" means "average over all possible outcomes". That is what "expected" means. It is a mathematical term whose meaning is already established.
You can safely ignore my previous reply, I think I finally see what you're saying. Not sure what to make of it yet, but I was definitely misinterpreting you.
Repeating your definition of a utility function over and over again doesn't oblige anybody else to use it. In particular, it doesn't oblige all those people who have argued for expected utility maximization in the past to have adopted it before you tried to force it on them.
A von Neumann-Morgenstern utility function (which is what people are supposed to maximize the expectation of) is a representation of a set of consistent preferences over gambles. That is all it is. If your proposal results in a set of consistent preferences over gambles (I see no particular reason for it not to, but I could be wrong) then it corresponds to expected utility maximization for some utility function. If it doesn't, then either it is inconsistent, or you have a beef with the axioms that runs deeper than an analogy to average utilitarianism.
"Expected" means expected value of utility function of possible outcomes, according to the probability distribution on the possible outcomes.