My take is that the concept of expected utility maximization is a mistake. In Eliezer's Coherent decisions imply consistent utilities, you can see the mistake where he writes:
From your perspective, you are now in Scenario 1B. Having observed the coin and updated on its state, you now think you have a 90% chance of getting $5 million and a 10% chance of getting nothing.
Reflectively stable agents are updateless. When they make an observation, they do not limit their caring as though all the possible worlds where their observation differs do not exist.
As far as I know, every argument for utility assumes (or implies) that whenever you make an observation, you stop caring about the possible worlds where that observation went differently.
The original Timeless Decision Theory was not updateless. Nor were any of the more traditional ways of thinking about decision. Updateless Decision Theory, and subsequent decision theories corrected this mistake.
Von Neumann did not notice this mistake because he was too busy inventing the entire field. The point where we discover updatelessness is the point where we are supposed to realize that all of utility theory is wrong. I think we failed to notice.
Ironically the community that was the birthplace of updatelessness became the flag for taking utility seriously. (To be fair, this probably is the birthplace of updatelessness because we took utility seriously.)
Unfortunately, because utility theory is so simple, and so obviously correct if you haven't thought about updatelessness, it ended up being assumed all over the place, without tracking the dependency. I think we use a lot of concepts that are built on the foundation of utility without us even realizing it.
(Note that I am saying here that utility theory is a theoretical mistake! This is much stronger than just saying that humans don't have utility functions.)
My personal take is that everything you wrote in this post is correct, and expected utility maximisers are neither the real threat, nor a great model for thinking about dangerous AI. Thanks for writing this up!
The key question I always focus on is: where do you get your capabilities from?
For instance, with GOFAI and ordinary programming, you have some human programmer manually create a model of the scenarios the AI can face, and then manually create a bunch of rules for what to do in order to achieve things. So basically, the human programmer has a bunch of really advanced capabilities, and they use them to manually build some simple capabilities.
"Consequentialism", broadly defined, represents an alternative class of ways to gain capabilities, namely choosing what to do based on it having the desired consequences. To some extent, this is a method humans uses, perhaps particularly the method the smartest and most autistic humans most use (which I suspect to be connected to LessWrong demographics but who knows...). Utility maximization captures the essence of consequentalism; there are various other things, such as multi-agency that one can throw on top of it, but those other things still mainly derive their capabilities from the core of utility maximization.
Self-supervised language models such as GPT-3 do not gain their capabilities from consequentialism, yet they have advanced capabilities nonetheless. How? Imitation learning, which basically works because of Aumann's agreement theorem. Self-supervised language models mimic human text, and humans do useful stuff and describe it in text, so self-supervised language models learn the useful stuff that can be described in text.
Risk that arises purely from language models or non-consequentialist RLHF might be quite interesting and important to study. I feel less able to predict it, though, partly because I don't know what the models will be deployed to do, or how much they can be coerced into doing, or what kinds of witchcraft are necessary to coerce the models into doing those things.
It is possible to me that imitation learning and RLHF can bring us to the frontier of human abilities, so that we have a tool that can solve tasks as well as the best humans can. However, I don't think it will be able to much exceed that frontier. This is still superhuman, because no human is as good as all the best humans at all the tasks. But it is not far-superhuman, even though I think being far-superhuman is possible, and a key part in it not being far-superhuman is that it cannot extend its capabilities. As such, I would expect consequentialism to be necessary for creating something that is far-superhuman.
I think many of the classical AI risk arguments apply to consequentialist far-superhuman AI.
If you're saying "let's think about a more general class of agents because EU maximization is unrealistic", that's fair, but note that you're potentially making the problem more difficult by trying to deal with a larger class with fewer invariants.
If you're saying "let's think about a distinct but not more general class of agents because that will be more alignable", then maybe, and it'd be useful to say what the class is, but: you're going to have trouble aligning something if you can't even know that it has some properties that are stable under self-reflection. An EU maximizer is maybe close to being stable under self-reflection and self-modification. That makes it attractive as a theoretical tool: e.g. maybe you can point at a good utility function, and then get a good prediction of what actually happens, relying on reflective stability; or e.g. maybe you can find nearby neighbors to EU maximization that are still reflectively stable and easier to align. It makes sense to try starting from scratch, but IMO this is a key thing that any approach will probably have to deal with.
My current take is that we don't have good formalisms for consequentialist goal-directed systems that are weaker than expected utility maximization, and therefore don't really know how to reason about them. I think this is main cause of overemphasis on EUM.
For example, completeness as stated in the VNM assumptions is actually a really strong property. Aumann wrote a paper on removing completeness, but the utility function is no longer unique.
Speaking for myself, I sometimes use "EU maximization" as shorthand for one of the following concepts, depending on context:
Hmm, I just did a search of my own LW content, and can't actually find any instances of myself doing this, which makes me wonder why I was tempted to type the above. Perhaps what I actually do is if I see someone else mention "EU maximization", I mentally steelman their argument by replacing the concept with one of the three above, if anyone of them would make a sensible substitution.
Do you have any actual examples of anyone talking about EU maximization lately, in connection with AI risk?
I think it depends on how you define expected utility. I agree that a definition that limits us only to analyzing end-state maximizers that seek some final state of the world is not very useful.
I don't think that for non-trivial AI agents, the utility function should or even can be defined as a simple function over the preferable final state of the world. U:Ω→R
This function does not take into account time and an intermediate set of predicted future states that the agent will possibly have preference over. The agent may have a preference for the final state of the universe but most likely and realistically it won't have that kind of preference except for some special strange cases. There are two reasons:
Any complex agent would likely have a utility function over possible actions that would be equal to the utility function of the set of predicted futures after action A vs the set of predicted futures without action A (or over differences between worlds in those futures). By action I mean possibly a set of smaller actions (hierarchy of actions - e.g. plans, strategies), it might not be atomic. Directly it cannot be easily computable so most likely this would be compressed to a set of important predicted future events on the level of abstraction that the agent cares about, which should constitute future worlds without action A and action A with enough approximation.
This is also how we evaluate actions. We evaluate outcomes in the short and long terms. We also care differently depending on time scope.
I say this because most sensible "alignment goals" like please don't kill humans are time-based. What does it mean not to kill humans? It is clearly not about the final state. Remember, Big Rip or Big Freeze. Maybe AGI can kill some for a year and then no more assuming the population will go up and some people are killed anyway so it does not matter long-term? No, this is also not about the non-final but long-term outcome. Really it is a function of intermediate states. Something like the integral of some function U'(dΩ) where dΩ is a delta between outcomes of action vs non-action, over time, which can be approximated and compressed into integral over the function of an event over multiple events until some time T being maximal sensible scope.
Most of the behaviors and preferences of humans are also time-scoped, and time-limited and take multiple future states into account, mostly short-scoped. I don't think that alignment goals can be even expressed in terms of simple end-goal (preferable final state of the world) as the problem partially comes from the attitude of eng goal justifying the means that are at the core of the utility function defined as U:Ω→R.
It seems plausible to me that even non-static human goals can be defined as utility functions over the set of differences in future outcomes (difference between two paths of events). What is also obvious to me is that we as humans are able to modify our utility function to some extent, but not very much. Nevertheless, for humans the boundaries between most baseline goals, preferences, and morality vs instrumental convergence goals are blurry. We have a lot of heuristics and biases so our minds work out some things more quickly and more efficiently than if we would on intelligence, thinking, and logic. The cost is lower consistency, less precision, and higher variability.
So I find it useful to think about agents as maximizers over utility function, but not defined as one final goal or outcome or state of the world. Rather one that maximizes the difference between two ordered sets of events in different time scopes to calculate the utility of an action.
I also don't think agents must be initially rationally stable with an unchangeable utility function. This is also a problem as an agent can have initially a set of preferences with some hierarchy or weights, but it also can reason that some of these are incompatible with others, that the hierarchy is not logically consistent, and might seek to change it for sake of consistency to be fully coherent.
I'm not an AGI, clearly, but it is just like I think about morality right now. I learned that killing is bad. But I still can question "why we don't kill?" and modify my worldview based on the answer (or maybe specify it in more detail in this matter). And it is a useful question as it says a lot about edge cases including abortion, euthanasia, war, etc. The same might happen for rational agents - as it might update their utility function to be stable and consistent, maybe even questioning some of the learned parts of the utility function in the process. Yes, you can say that if you can change that then it was not your terminal goal. Nevertheless, I can imagine agents with no terminal core goals at all. I'm not even sure if we as humans have any core terminal goals (maybe except avoiding death and own harm in the case of most humans in most circumstances... but some overcome that as Thích Quảng Đức did).
Epistemic Status
Unsure[1], partially noticing my own confusion. Hoping Cunningham's Law can help resolve it.
Related Answer
Confusions About Arguments From Expected Utility Maximisation
Some MIRI people (e.g. Rob Bensinger) still highlight EU maximisers as the paradigm case for existentially dangerous AI systems. I'm confused by this for a few reasons:
I don't expect the systems that matter (in the par human or strongly superhuman regime) to be expected utility maximisers. I think arguments for AI x-risk that rest on expected utility maximisers are mostly disconnected from reality. I suspect that discussing the perils of expected utility maximisation in particular — as opposed to e.g. dangers from powerful (consequentialist?) optimisation processes — is somewhere between being a distraction and being actively harmful[3].
I do not think expected utility maximisation is the limit of what generally capable optimisers look like[4].
Arguments for Expected Utility Maximisation Are Unnecessary
I don't think the case for existential risks from AI safety rest on expected utility maximisation. I kind of stopped alieving expected utility maximisers a while back (only recently have I synthesised explicit beliefs that reject it), but I still plan on working on AI existential safety, because I don't see the core threat as resulting from expected utility maximisation.
The reasons I consider AI an existential threat mostly rely on:
I do not actually expect extinction near term, but it's not the only "existential catastrophe":
I optimised for writing this quickly. So my language may be stronger/more confident that I actually feel. I may not have spent as much time accurately communicating my uncertainty as may have been warranted.
Correct me if I'm mistaken, but I'm under the impression that RL is the main training paradigm we have that selects for agents.
I don't necessarily expect that our most capable systems would be trained via reinforcement learning, but I think our most agentic systems would be.
There may be significant opportunity cost via diverting attention from other more plausible pathways to doom.
In general, I think exposing people to bad arguments for a position is a poor persuasive strategy as people who dismiss said bad arguments may (rationally) update downwards on the credibility of the position.
I don't necessarily think agents are that limit either. But as "Why Subagents?" shows, expected utility maximisers aren't the limit of idealised agency.