All of Sniffnoy's Comments + Replies

I've run this several times at OBNYC, it's gone pretty well. Generally we didn't bother with scoring. One issue with scoring is needing to come up with what counts for numerical questions. Although we tried to do that anyway, because we wanted to score individual questions even if we weren't keeping score overall. For many things you can use "order of magnitude and first digit", but that doesn't work well for everything. Dates we generally did plus or minus 10 years. But it may need to vary a bit depending on just what the question. Maybe plus or mi... (read more)

2Screwtape
I've found that a lot of exercises want a big list of questions. (Calibration Trivia, Dissent Collusion, Outrangeous, and Pastcasting off the top of my head.) I should crowdsource more of these or spend more time adding questions somehow. I'm a bit confused on your proposed change- if you roll a 1 or a 2 you can say you looked up the answer, or you can lie and say you didn't. Whether you actually look up the answer seems irrelevant? Is it that misleading the Lonesome is easier if the Collective knows the answer? Thank you for the report from OBNYC! It's good hear this has gone well :) Does it seem like it's working as practice?

We could also point to sleepwalkers of various sorts: even when executing complex actions (like murdering someone), I've never seen any accounts which mention deeply felt emotions. (WP emphasizes their dullness and apathetic affect.)

Nitpick: Sleepwalking proper apparently happens during non-REM sleep; acting out a dream during REM sleep is different and has its own name. Although it seems like sleepwalkers may also be dreaming somehow even though they aren't in REM sleep? I don't know -- this is definitely not my area -- and arguably none of this is r... (read more)

8gwern
Yeah, my point was simply that we have "p-zombies" of sorts involving sleep, which demonstrate that you can take complex actions conscious-like reacting to the real world during sleep which would normally (if done while waking) seem to entail intense emotion but appear to not involve real emotion much or at all. So that helps support the idea that in a different part of sleep, you could be taking complex actions conscious-like reacting to a mental world which would seem to entail intense emotions but aside from the remembered content and some weak physiological traces like sweat or heart-rate, do not appear to involve real emotion much or at all. (Which part of 'sleep' the former happens in is not too important; but of course it is better if it can happen in REM proper, to more strongly support the thesis that it could happen elsewhere during REM.)

Ha! OK, that is indeed nasty. Yeah I guess CASes can solve this kind of problem these days, can't they? Well -- I say "these days" as if it this hasn't been the case for, like, my entire life, I've just never gotten used to making routine use of them...

One annoying thing in reading Chapter 3 -- chapter 3 states that for l=2,4,8, the optimal scoring rules can be written in terms of elementary functions. However, you only actually give the full formula for the case l=8 (for l=2 you give it on half the interval). What are the formulas for the other cases?

(But also, this is really cool, thanks for posting this!)

4Eric Neyman
Thanks! I think the reason I didn't give those expressions is that they're not very enlightening. See here for l = 2 on (0, 1/2] and here for l = 4 on [1/2, 1).

I think some cases cases of what you're describing as derivation-time penalties may really be can-you-derive-that-at-all penalties. E.g., with MWI and no Born rule assumed, it doesn't seem that there is any way to derive it. I would still expect a "correct" interpretation of QM to be essentially MWI-like, but I still think it's correct to penalize MWI-w/o-Born-assumption, not for the complexity of deriving the Born rule, but for the fact that it doesn't seem to be possible at all. Similarly with attempts to eliminate time, or its distinction from space, from physics; it seems like it simply shouldn't be possible in such a case to get something like Lorentz invariance.

Why do babies need so much sleep then?

Given that at the moment we don't really understand why people need to sleep at all, I don't think this is a strong argument for any particular claimed function.

1mikbp
That makes total sense, true.

Oh, that's a good citation, thanks. I've used that rough argument in the past, knowing I'd copied it from someone, but I had no recollection of what specifically or that it had been made more formal. Now I know!

My comment above was largely just intended as "how come nobody listens when I say it?" grumbling. :P

I should note that this is more or less the same thing that Alex Mennen and I have been pointing out for quite some time, even if the exact framework is a little different. You can't both have unbounded utilities, and insist that expected utility works for infinite gambles.

IMO the correct thing to abandon is unbounded utilities, but whatever assumption you choose to abandon, the basic argument is an old one due to Fisher, and I've discussed it in previous posts! (Even if the framework is a little different here, this seems essentially similar.)

I'm glad t... (read more)

4paulfchristiano
I agree that "unbounded utilities" don't refer to anything at all in the usual sense of "utility function" and that this observation is basically as old as VNM itself. I usually cite de Blanc 2007 to point out that unbounded utilities are just totally busted for non-dogmatic priors (but this is also a formalization of a much older argument about "contagion"). The point of these posts was to observe that this isn't just an artifact of utility functions, and that changing the formalism doesn't help you get around the problems. So this isn't really an argument against utility functions, it's a much more direct argument against a certain kind of preferences. There just don't exist any transitive preferences with unbounded-utility-like-behavior and weak outcome-lottery dominance.

Yeah, that sounds about right to me. I'm not saying that you should assume such people are harmless or anything! Just that, like, you might want to try giving them a kick first -- "hey, constant vigilance, remember?" :P -- and see how they respond before giving up and treating them as hostile.

This seems exactly backwards, if someone makes uncorrelated errors, they are probably unintentional mistakes. If someone makes correlated errors, they are better explained as part of a strategy.

I mean, there is a word for correlated errors, and that word is "bias"; so you seem to be essentially claiming that people are unbiased? I'm guessing that's probably not what you're trying to claim, but that is what I am concluding? Regardless, I'm saying people are biased towards this mistake.

Or really, what I'm saying it's the same sort of phenomenon that Eli... (read more)

5Benquo
In most cases it seems intentional but not deliberate. People will resist pressure to change the pattern, or find new ways to execute it if the specific way they were engaged in this bias is effectively discouraged, but don't consciously represent to themselves their intent to do it or engage in explicit means-ends reasoning about it.

I don't think this follows. I do not see how degree of wrongness implies intent. Eliezer's comment rhetorically suggests intent ("trolling") as a way of highlighting how wrong the person is; he is free to correct me if I am wrong, but I am pretty sure that is not an actual suggestion of intent, only a rhetorical one.

I would say moreover, that this is the sort of mistake that occurs, over and over, by default, with no intent necessary. I might even say that it is avoiding, not committing, this sort of mistake, that requires intent. Because this sort of ... (read more)

4Benquo
This seems exactly backwards, if someone makes uncorrelated errors, they are probably unintentional mistakes. If someone makes correlated errors, they are better explained as part of a strategy. I can imagine, after reading the sequences, continuing to have the epistemic modesty bias in my own thoughts, but I don't see how I could have been so confused as to refer to it in conversation as a valid principle of epistemology.

I want to more or less second what River said. Mostly I wouldn't have bothered replying to this... but your line of "today around <30" struck me as particularly wrong.

So, first of all, as River already noted, your claim about "in loco parentis" isn't accurate. People 18 or over are legally adults; yes, there used to be a notion of "in loco parentis" applied to college students, but that hasn't been current law since about the 60s.

But also, under 30? Like, you're talking about grad students? That is not my experience at all. Undergrads are still tre... (read more)

I'm not involved with the Bay Area crowd but I remember seeing things about how Leverage is a scam/cult years ago; I was surprised to learn it's still around...? I expected most everyone would have deserted it after that...

This reminds me of the focusing/circling/NVC discussions, one group (to which I belonged) was like "this is obviously culty mindfuckery, can't you see" and the other group couldn't see, and arguments couldn't bridge that gap. It's like how some people can recognize bullying and others will say "boys will be boys", while looking at the exact same situation.

I do worry about "ends justify the means" reasoning when evaluating whether a person or project was or wasn't "good for the world" or "worth supporting". This seems especially likely when using an effective-altruism-flavored lens that only a few people/organizations/interventions will matter orders of magnitude more than others. If one believes that a project is one of very few projects that could possibly matter, and the future of humanity is at stake - and also believes the project is doing something new/experimental that current civilization is inadequ

... (read more)

Seems to me the story in the original yak-shaving story falls into case 2 -- the thing to do is to forget about borrowing the EZPass and just pay the toll!

There used to be an Ann Arbor LW meetup group, actually, back when I lived there -- it seems to be pretty dead now best I can tell but the mailing list still exists. It's A4R-A2@googlegroups.com; I don't know how relevant this is to you, since you're trying to start a UM group and many of the people on that list will likely not be UM-affiliated, but you can at least try recruiting from there (or just restarting it if you're not necessarily trying to specifically start a UM group). It also used to have a website, though I can't find it at the moment, and ... (read more)

2DirectedEvolution
That’s a helpful place to start, thank you!

Oh, huh -- looks like this paper is the summary of the blog series that "Slime Mold Time Mold" has been written about it? Guess I can read this paper to skip to the end, since not all of it is posted yet. :P

Yeah. You can use language that is unambiguously not attack language, it just takes more effort to avoid common words. In this respect it's not much unlike how discussing lots of other things seriously requires avoiding common but confused words!

I'm reminded of this paper, which discusses a smaller set of two-player games. What you call "Cake Eating" they call the "Harmony Game". They also use the more suggestive variable names -- which I believe come from existing literature -- R (reward), S (sucker's payoff), T (temptation), P (punishment) instead of (W, X, Y, Z). Note that in addition to R > P (W > Z) they also added the restrictions T > P (Y > Z) and R > S (W > X) so that the two options could be meaningfully labeled "cooperate" and "defect" instead of "Krump" and "Flitz" ... (read more)

I suppose so. It is at least a different problem than I was worried about...

Huh. Given the negative reputation of bioethics around here -- one I hadn't much questioned, TBH -- most of these are suprisingly reasonable. Only #10, #16, and #24 really seemed like the LW stereotype of the bioethics paper that I would roll my eyes at. Arguably also #31, but I'd argue that one is instead alarming in a different way.

Some others seemed like bureaucratic junk (so, neither good nor bad), and others I think the quoted sections didn't really give enough information to judge; it is quite possible that a few more of these would go under the s... (read more)

4MikkW
Wouldn't the presence of "bureaucratic junk" be evidence towards a field having problems?

Consider a modified version of the prisoner's dilemma. This time, the prisoners are allowed to communicate, but they also have to solve an additional technical problem, say, how to split the loot. They may start with agreeing on not betraying each other to the prosecutors, but later one of them may say: "I've done most of the work. I want 70% of the loot, otherwise I am going to rat on you." It's easy to see how the problem would escalate and end up in the prisoners betraying each other.

Minor note, but I think you could just talk about a [bargaining gam... (read more)

I just explained why (without more specific theories of in exactly what way the gravity would become delocalized from the visible mass) the bullet cluster is not evidence one way or the other.

Now, you compare the extra fields of modified gravity to epicycles -- as in, post-hoc complications grafted on to a theory to explain a particular phenomenon. But these extra fields are, to the best of my understanding, not grafted on to explain such delocalization; they're the actual basic content of the modified gravity theories and necessary to obtain a workable t... (read more)

I feel like this really misses the point of the whole "non-central fallacy" idea. I would say, categories are heuristics and those heuristics have limits. When the category gets strained, the thing to do is to stop arguing using the category and start arguing the particular facts without relation to the category ("taboo your words").

You're saying that this sort of arguing-via-category is useful because it's actually aguing-via-similarity; but I see the point of Scott/Yvain's original article being that such arguing via similarity simply isn't useful in s... (read more)

Good post. Makes a good case. I wasn't aware of the evidence from galactic cluster lensing; that's pretty impressive. (I guess not as much as the CMB power spectrum, but that I'd heard about before. :P )

But, my understanding is that the Bullet Cluster is actually not the strong evidence it's claimed to be? My understanding of modified gravity theories is that, since they all work by adding extra fields, it's also possible for those to have gravity separated from visible matter, even if no dark matter is present. (See e.g.. here... of course in this po... (read more)

0[anonymous]
And with enough epicycles you can fit the motion of planets with geocentricism. If MOND supporters can dismiss Bullet Cluster they'll dismiss any future evidence, too.

"Cyan" isn't a basic color term in English; English speakers ordinarily consider cyan to be a variant of blue, not something basically separate. Something that is cyan could also be described in English as "blue". As opposed to say, red and pink -- these are both basic color terms in English; an English speaker would not ordinarily refer to something pink as "red", or vice versa.

Or in other words: Color words don't refer to points in color space, they refer to regions, which means that you can look at how those regions overlap -- some may be subsets of o... (read more)

Wow!

I guess a thing that still bugs me after reading the rest of the comments is, if it turns out that this vaccine only offers protection against inhaling the virus though the nose, how much does that help when one considers that one could also inhale it through the mouth? Like, I worry that after taking this I'd still need to avoiding indoor spaces with other people, etc, which would defeat a lot of the benefit of it.

But, if it turns out that it does yield antibodies in the blood, then... this sounds very much worth trying!

8Dentin
My understanding is that it helps a lot. The biggest benefit seems to be that the immune system is primed in at least some fashion; it knows what to look for, and it has readily available tools that should be effective.  It doesn't have to take a day or a week to try random things before it finally discovers a particularly effective antibody and gets the production chain ramped up to start a proper immune response. Instead, your immune system will very quickly get a signal it understands as bad and can immediately start ramping up when it does detect the virus. Keep in mind that the commercial vaccines don't have 100% success rate in that some people still get sick, but the 'priming' of the immune response is still there.  I believe this is why the death rate / severe complications rate is effectively zero for immunized patients, even though it's possible to get sick. (Again, my understanding.  I would very much appreciate correction/clarifications here.)

So, why do we perceive so many situations to be Prisoner's Dilemma -like rather than Stag Hunt -like?

I don't think that we do, exactly. I think that most people only know the term "prisoners' dilemma" and haven't learned any more game theory than that; and then occasionally they go and actually attempt to map things onto the Prisoners' Dilemma as a result. :-/

That sounds like it might have been it?

Sorry, but after reading this I'm not very clear on just what exactly the "Magic Formula" refers to. Could you state it explicitly?

7Martin Sustrik
Fixed:

Oops, turns out I did misremember -- Savage does not in fact put the proof in his book. You have to go to Fishburn's book.

I've been reviewing all this recently and yeah -- for anyone else who wants to get into this, I'd reccommend getting Fishburn's book ("Utility Theory for Decision Making") in addition to Savage's "Foundations of Statistics". Because in addition to the above, what I'd also forgotten is that Savage leaves out a bunch of the proofs. It's really annoying. Thankfully in Fishburn's treatment he went and actually elaborated all the proofs

... (read more)

Oh, I see. I misread your comment then. Yes, I am assuming one already has the ability to discern the structure of an argument and doesn't need to hire someone else to do that for you...

What I said above. Sorry, to be clear here, by "argument structure" I don't mean the structure of the individual arguments but rather the overall argument -- what rebuts what.

(Edit: Looks like I misread the parent comment and this fails to respond to it; see below.)

5Vaniver
To be clear as well, the rhetorical point underneath my question is that I don't think your heuristic is all that useful, and seems grounded in generalization from too few examples without searching for counterexamples. Rather than just attacking it directly like Gordon, I was trying to go up a meta-level, to just point at the difficulty of 'buying' methods of determining expertise, because you need to have expertise in distinguishing the market there. (In general, when someone identifies a problem and you think you have a solution, it's useful to consider whether your solution suffers from that problem on a different meta-level; sometimes you gain from sweeping the difficulty there, and sometimes you don't.)

This is a good point (the redemption movement comes to mind as an example), but I think the cases I'm thinking of and the cases you're describing look quite different in other details. Like, the bored/annoyed expert tired of having to correct basic mistakes, vs. the salesman who wants to initiate you into a new, exciting secret. But yeah, this is only a quick-and-dirty heuristic, and even then only good for distinguishing snake oil; it might not be a good idea to put too much weight on it, and it definitely won't help you in a real dispute ("Wait, both s

... (read more)

Given a bunch of people who disagree, some of whom are actual experts and some of whom are selling snake oil, expertise yourself, there are some further quick-and-dirty heuristics you can use to tell which of the two groups is which. I think basically my suggestion can be best summarized at "look at argument structure".

The real experts will likely spend a bunch of time correct popular misconceptions, which the fakers may subscribe to. By contrast, the fakers will generally not bother "correcting" the truth to their fakery, because why would they? They'r

... (read more)
5[anonymous]
Here's another: probing into their argument structure a bit and checking if they can keep it from collapsing under its own weight. https://www.lesswrong.com/posts/wyyfFfaRar2jEdeQK/entangled-truths-contagious-lies
4Vaniver
And how does one distinguish snake oil salesmen and real experts when it comes to identifying argument structure and what it implies?
The real experts will likely spend a bunch of time correct popular misconceptions, which the fakers may subscribe to. By contrast, the fakers will generally not bother "correcting" the truth to their fakery, because why would they? They're trying to sell to unreflective people who just believe the obvious-seeming thing; someone who actually bothered to read corrections to misconceptions at any point is likely too savvy to be their target audience.

Using this as a heuristic would often backfire on you as stated, because there's a certain ... (read more)

The real experts will likely spend a bunch of time correct popular misconceptions, which the fakers may subscribe to. By contrast, the fakers will generally not bother "correcting" the truth to their fakery, because why would they? They're trying to sell to unreflective people who just believe the obvious-seeming thing; someone who actually bothered to read corrections to misconceptions at any point is likely too savvy to be their target audience.

This seems to rely on the fakes knowing they are fakes. I agree that is a problem and your heu... (read more)

Well, it's worth noting that P7 is introduced to address gambles with infinitely many possible outcomes, regardless of whether those outcomes are bounded or not (which is the reason I argue above you can't just get rid of it). But yeah. Glad that's cleared up now! :)

Ahh, thanks for clarifying. I think what happened was that your modus ponens was my modus tollens -- so when I think about my preferences, I ask "what conditions do my preferences need to satisfy for me to avoid being exploited or undoing my own work?" whereas you ask something like "if my preferences need to correspond to a bounded utility function, what should they be?" [1]

That doesn't seem right. The whole point of what I've been saying is that we can write down some simple conditions that ought to be true in order to avoid being exploitable or othe

... (read more)
4Isnasene
Thanks for the reply. I re-read your post and your post on Savage's proof and you're right on all counts. For some reason, it didn't actually click for me that P7 was introduced to address unbounded utility functions and boundedness was a consequence of taking the axioms to their logical conclusion.

Here's a quick issue I only just noticed but which fortunately is easily fixed:

Above I mentioned you probably want to restrict to a sigma-algebra of events and only allow measurable functions as actions. But, what does measurable mean here? Fortunately, the ordering on outcomes (even without utility) makes measurability meaningful. Except this puts a circularity in the setup, because the ordering on outcomes is induced from the ordering on actions.

Fortunately this is easily patched. You can start with the assumption of a total preorder on outcomes (con

... (read more)

(This is more properly a followup to my sibling comment, but posting it here so you'll see it.)

I already said that I think that thinking in terms of infinitary convex combinations, as you're doing, is the wrong way to go about it; but it took me a bit to put together why that's definitely the wrong way.

Specifically, it assumes probability! Fishburn, in the paper you link, assumes probability, which is why he's able to talk about why infinitary convex combinations are or are not allowed (I mean, that and the fact that he's not necessarily arbitrary actions

... (read more)
3Richard_Kennaway
Savage doesn't assume probability or utility, but their construction is a mathematical consequence of the axioms. So although they come later in the exposition, they mathematically exist as soon as the axioms have been stated. I am still thinking about that, and may be some time. As a general outline of the situation, you read P1-7 => bounded utility as modus ponens: you accept the axioms and therefore accept the conclusion. I read it as modus tollens: the conclusion seems wrong, so I believe there is a flaw in the axioms. In the same way, the axioms of Euclidean geometry seemed very plausible as a description of the physical space we find ourselves in, but conflicts emerged with phenomena of electromagnetism and gravity, and eventually they were superseded as descriptions of physical space by the geometry of differential manifolds. It isn't possible to answer the question "which of P1-7 would I reject?" What is needed to block the proof of bounded utility is a new set of axioms, which will no doubt imply large parts of P1-7, but might not imply the whole of any one of them. If and when such a set of axioms can be found, P1-7 can be re-examined in their light.

Apologies, but it sounds like you've gotten some things mixed up here? The issue is boundedness of utility functions, not whether they can take on infinity as a value. I don't think anyone here is arguing that utility functions don't need to be finite-valued. All the things you're saying seem to be related to the latter question rather than the former, or you seem to be possibly conflating them?

In the second paragraph perhaps this is just an issue of language -- when you say "infinitely high", do you actually mean "aribtrarily high"? -- but in the first

... (read more)
1Isnasene
Ahh, thanks for clarifying. I think what happened was that your modus ponens was my modus tollens -- so when I think about my preferences, I ask "what conditions do my preferences need to satisfy for me to avoid being exploited or undoing my own work?" whereas you ask something like "if my preferences need to correspond to a bounded utility function, what should they be?" [1]. As a result, I went on a tangent about infinity to begin exploring whether my modified notion of a utility function would break in ways that regular ones wouldn't. I agree, one shouldn't conclude anything without a theorem. Personally, I would approach the problem by looking at the infinite wager comparisons discussed earlier and trying to formalize them into additional rationality condition. We'd need * an axiom describing what it means for one infinite wager to be "strictly better" than another. * an axiom describing what kinds of infinite wagers it is rational to be indifferent towards Then, I would try to find a decisioning-system that satisfies these new conditions as well as the VNM-rationality axioms (where VNM-rationality applies). If such a system exists, these axioms would probably bar it from being represented fully as a utility function. If it didn't, that'd be interesting. In any case, whatever happens will tell us more about either the structure our preferences should follow or the structure that our rationality-axioms should follow (if we cannot find a system). Of course, maybe my modification of the idea of a utility function turns out to show such a decisioning-system exists by construction. In this case, modifying the idea of a utility function would help tell me that my preferences should follow the structure of that modification as well. Does that address the question? [1] From your post:

Oh, so that's what you're referring to. Well, if you look at the theorem statements, you'll see that P=P_d is an axiom that is explicitly called out in the theorems where it's assumed; it's not implictly part of Axiom 0 like you asserted, nor is it more generally left implicit at all.

but the important part is that last infinite sum: this is where all infinitary convex combinations are asserted to exist. Whether that is assigned to "background setup" or "axioms" does not matter. It has to be present, to allow the construction of St. Petersburg gambles.

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Savage does not actually prove bounded utility. Fishburn did this later, as Savage footnotes in the edition I'm looking at, so Fishburn must be tackled.

Yes, it was actually Fishburn that did that. Apologies if I carelessly implied it was Savage.

IIRC, Fishburn's proof, formulated in Savage's terms, is in Savage's book, at least if you have the second edition. Which I think you must, because otherwise that footnote wouldn't be there at all. But maybe I'm misremembering? I think it has to be though...

In Savage's formulation, from P1-P6 he derives The

... (read more)
2Sniffnoy
Oops, turns out I did misremember -- Savage does not in fact put the proof in his book. You have to go to Fishburn's book. I've been reviewing all this recently and yeah -- for anyone else who wants to get into this, I'd reccommend getting Fishburn's book ("Utility Theory for Decision Making") in addition to Savage's "Foundations of Statistics". Because in addition to the above, what I'd also forgotten is that Savage leaves out a bunch of the proofs. It's really annoying. Thankfully in Fishburn's treatment he went and actually elaborated all the proofs that Savage thought it OK to skip over... (Also, stating the obvious, but get the second edition of "Foundations of Statistics", as it fixes some mistakes. You probably don't want just Fishburn's book, it's fairly hard to read by itself.)

Fishburn (op. cit., following Blackwell and Girschick, an inaccessible source) requires that the set of gambles be closed under infinitary convex combinations.

Again, I'm simply not seeing this in the paper you linked? As I said above, I simply do not see anything like that outside of section 9, which is irrelevant. Can you point to where you're seeing this condition?

I shall take a look at Savage's axioms and see what in them is responsible for the same thing.

In the case of Savage, it's not any particular axiom, but rather the setup. An action is

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2Richard_Kennaway
In Fishburn's "Bounded Expected Utility", page 1055, end of first paragraph (as cited previously): That depends on some earlier definitions, e.g. is a certain set of probability distributions (the “d” stands for “discrete”) defined with reference to some particular -algebra, but the important part is that last infinite sum: this is where all infinitary convex combinations are asserted to exist. Whether that is assigned to "background setup" or "axioms" does not matter. It has to be present, to allow the construction of St. Petersburg gambles. Will address the rest of your comments later.

Huh. This would need some elaboration, but this is definitely the most plausible way around the problem I've seen.

Now (in Savage's formalism) actions are just functions from world-states to outcomes (maybe with a measurability condition), so regardless of your prior it's easy to construct the relevant St. Petersburg gambles if the utility function is unbounded. But seems like what you're saying is, if we don't allow arbitrary actions, then the prior could be such that, not only are none of the permitted actions St. Petersburg gambles, but also this remains the case even after future updates. Interesting! Yeah, that just might be workable...

OK, so going by that you're suggesting, like, introducing varying caps and then taking limits as the cap goes to infinity? It's an interesting idea, but I don't see why one would expect it to have anything to do with preferences.

1Isnasene
Yes, I think that's a good description. In my case, it's a useful distinction because I'm the kind of person who thinks that showing that a real thing is infinite requires an infinite amount of information. This means I can say things like "my utility function scales upward linearly with the number of happy people" without things breaking because it is essentially impossible to convince me that any set of finite action could legitimately cause a literally infinite number of happy people to exist. For people who believe they could achieve actually infinitely high values in their utility functions, the issues you point out still hold. But I think my utility function is bounded by something eventually even if I can't tell you what that boundary actually is.

You should check out Abram's post on complete class theorems. He specifically addresses some of the concerns you mentioned in the comments of Yudkowsky's posts.

So, it looks to me like what Abrams is doing -- once he gets past the original complete class theorem -- is basically just inventing some new formalism along the lines of Savage. I think it is very misleading to refer to this as "the complete class theorem" -- how on earth was I supposed to know that this was what was being referred to when "the complete class theorem" was mentioned, when it res

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I think you've misunderstood a fair bit. I hope you don't mind if I address this slightly out of order.

Or if infinite utilities are not immediately a problem, then by a more complicated argument, involving constructing multiple St. Petersburg-type combinations and demonstrating that the axioms imply that there both should and should not be a preference between them.

This is exactly what Fishburn does, as I mentioned above. (Well, OK, I didn't attribute it to Fishburn, I kind of implicitly misattributed it to Savage, but it was actually Fishburn; I did

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Or if you have some formalism where preferences can be undefined (in a way that is distinct from indifference), by all means explain it... (but what happens when you program these preferences into an FAI and it encounters this situation? It has to pick. Does it pick arbitrarily? How is that distinct from indifference?)

A short answer to this (something longer later) is that an agent need not have preferences between things that it is impossible to encounter. The standard dissolution of the St. Petersberg paradox is that nobody can offer that gamble. Even th... (read more)

Is there a reason we can't just solve this by proposing arbitrarily large bounds on utility instead of infinite bounds? For instance, if we posit that utility is bounded by some arbitrarily high value X, then the wager can only payout values X for probabilities below 1/X.

I'm not sure what you're asking here. An individual decision-theoretic utility function can be bounded or it can be unbounded. Since decision-theoretic utility functions can be rescaled arbitrarily, naming a precise value for the bounds is meaningless; so like we could just assume the

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1Isnasene
Say our utility function assigns an actual thing in the universe with value V1 and the utility function is bounded by value X. What I'm saying is that we can make the problem go away by assuming bounded utility but without actually having to define the ratio between V1 and X as a specific finite number (this would not change upon scaling). This means that, if your utility function is something like "number of happy human beings", you don't have to worry about your utility function breaking if the maximum number of happy human beings is larger than you expected since you never have to define such an expectation. See my sub-sub-reply to Eigil Rischel's sub-reply for elaboration.

Yes, thanks, I didn't bother including it in the body of the post but that's basically how it goes. Worth noting that this:

Both of these wagers have infinite expected utility, so we must be indifferent between them.

...is kind of shortcutting a bit (at least as Savage/Fishburn[0] does it; he proves indifference between things of infinite expected utility separately after proving that expected utility works when it's finite), but that is the essence of it, yes.

(As for the actual argument... eh, I don't have it in front of me and don't feel like rederivi

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By "a specific gamble" do you mean "a specific pair of gambles"? Remember, preferences are between two things! And you hardly need a utility function to express a preference between a single pair of gambles.

I don't understand how to make sense of what you're saying. Agent's preferences are the starting point -- preferences as in, given a choice between the two, which do you pick? It's not clear to me how you have a notion of preference that allows for this to be undefined (the agent can be indifferent, but that's distinct).

I mean, you could try to come

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3FactorialCode
This is true, then it would only be between a specific subset of gambles. I think you should be able to set things up so that you never encounter a pair of gambles where this is undefined. I'll illustrate with an example. Suppose you start with a prior over the integers, such that: p(n) = (C/F(n)) where F(n) is a function that grows really fast and C is a normalization constant. Then the set of gambles that we're considering would be posteriors on the integers given that they obey certain properties. For instance, we could ask the agent to choose between the posterior over integers given that n is odd vs the posterior given that n is even. I'm pretty sure that you can construct an agent that behaves as if it had an unbounded utility function in this case. So long as the utility associated with an integer n grows sufficiently slower than F(N), all expectations over posteriors on the integers should be well defined. If you were to build an FAI this way, it would never end up in a belief state where the expected utility diverges between two outcomes. The expected utility would be well defined over any posterior on it's prior, so it's choice given a pair of gambles would also be well defined for any belief state it could find itself in.
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