I believe that the disagreement is mostly about what happens before we build powerful AGI. I think that weaker AI systems will already have radically transformed the world, while I believe fast takeoff proponents think there are factors that makes weak AI systems radically less useful. This is strategically relevant because I'm imagining AGI strategies playing out in a world where everything is already going crazy, while other people are imagining AGI strategies playing out in a world that looks kind of like 2018 except that someone is about to get a decisive strategic advantage.
Huh, I think this is most useful framing of the Slow/Fast takeoff paradigm I've found. Normally when I hear about the slow takeoff strategy I think it comes with a vague sense of "and therefore, it's not worth worrying out because our usual institutions will be able to handle it."
I'm not sure if I'm convinced about the continuous takeoff, but it at least seems plausible. It still seems to me that recursive self improvement should be qualitatively different - not necessarily resulting in a "discontinuitous jump" but changing the shape of the curve.
The curve below is a bit sharper than I meant it to come out, I had some trouble getting photoshop to cooperate.
More thoughts to come. I agree with Qiaochu that this is a good "actually think for N minutes" kinda post.
100% I visualised the above graph and wanted to draw it but didn't feel like I had the technical skills. Thanks.
It still seems to me that recursive self improvement should be qualitatively different
Could you say more about this intuition?
When I think of an AGI system engaging in RSI, I imagine it reasoning in a very general, first principles sort of way that, "I want to improve myself, and I run on TPUs, so I should figure out how to make better TPUs." But at the point that we have a system that can do that, we're already going to be optimizing the fuck out of TPUs. And we're going to be using all our not-quite-so-general systems to search for other things to optimize.
So where does the discontinuity (or curve shape change) come from?
This highlights perhaps a different thing, which is that... it'd seem very strange to me if the benefits from RSI exactly mapped onto an existing curve.
(This makes me think of an old Scott Alexander post reviewing the Great Stagnation, about how weird it is that all these economic curves seem pretty straight forwardly curvy. So this may be a domain where reality is normal and my intuitions are weird.)
There's another thing that bothers me too, which is the sheer damnable linearity of the economic laws. The growth of science as measured in papers/year; the growth of innovation as measured in patents; the growth of computation as measured by Moore's Law; the growth of the economy as measured in GDP. All so straight you could use them to hang up a picture. These lines don't care what we humans do, who we vote for, what laws we pass, what we invent, what geese that lay long-hanging fruit have or have not been killed. The Gods of the Straight Lines seem right up there with the Gods of the Copybook Headings in the category of things that tend to return no matter how hard you try to kick them away. They were saying back a few decades ago Moore's Law would stop because of basic physical restrictions on possible transistor size, and we worked around those, which means the Gods of the Straight Lines are more powerful than physics.
This is one of my major go-to examples of this really weird linear phenomenon:

150 years of a completely straight line! There were two world wars in there, the development of artificial fertilizer, the broad industrialization of society, the invention of the car. And all throughout the line just carries one, with no significant perturbations.
I'm confused. Moore's law, GDP growth etc. are linear in log-space. That graph isn't. Why are these spaces treated as identical for the purposes of carrying the same important and confusing intuition? (E.g. I imagine one could find lots of weird growth functions that are linear in some space. Why are they all important?)
Hmm, in either case a function being linear in a very easy to describe space (i.e. log, log-log or linear) highlights that the relationship the function describes is extremely simple, and seems to be independent of most factors that vary drastically over time. I expect the world to be stochastic and messy, with things going up and down for random reasons and with things over time going up and down quite a bit for very local reasons, but these graphs do not seem to conform with that intuition in a way that I don't easily know how to reconcile.
Thanks for writing this! Your point about chimps vs. humans was new to me and I'll chew on it.
Because I think this post is important enough I'm gonna really go above and beyond here: I'm gonna set a timer and think for 5 minutes, with paper, before writing the rest of my comment.
Okay, that was fun. What I got out of reading your post twice (once before writing this and once during the 5-minute timer) was basically the following. Let me know if this is an accurate summary of your position:
AI researchers will try to optimize AI to be as useful as possible. There are many tradeoffs that need to be navigated in order to do this, e.g. between universality and speed, and the Pareto boundary describing all of these tradeoffs is likely to grow slowly / continuously. So we probably won't see fast / discontinuous Pareto improvements in available AIs.
I find this reasonably persuasive, but I'm not convinced the positions you've described as slow takeoff vs. fast takeoff are what other people mean when they talk about slow vs. fast takeoff.
I'd be interested to see you elaborate on this:
There is another reason I’m skeptical about hard takeoff from universali...
That's an accurate summary of my position.
I agree that some people talking about slow takeoff mean something stronger (e.g. "no singularity ever"), but I think that's an unusual position inside our crowd (and even an unusual position amongst thoughtful ML researchers), and it's not e.g. Robin's view (who I take as a central example of a slow takeoff proponent).
Cool. It's an update to my models to think explicitly in terms of the behavior of the Pareto boundary, as opposed to in terms of the behavior of some more nebulous "the current best AI." So thanks for that.
Robin makes a lot of more detailed claims (e.g. about things being messy and having lots of parts) that are irrelevant to this particular conclusion. I disagree with many of the more detailed claims, and think they distract from the strongest part of the argument in this case.
Since there are some aspects of your version of "slow" takeoff that have been traditionally associated with the "fast" view, (e.g. rapid transformation of society), I'm tempted to try to tease apart what we care about in the slow vs fast discussion into multiple questions:
1) How much of a lead will one team need to have over others in order to have a decisive strategic advantage...
a) in wall clock time?
b) in economic doublings time?
2) How much time do we have to solve hard alignment problems...
a) in wall clock time?
b) in economic doublings time?
It seems that one could plausibly hold a "slow" view for some of these questions and a "fast" view for others.
For example, maybe Alice thinks that GDP growth will accelerate, and that there are gains to scale/centralization for AI projects, but that it will be relatively easy for human operators to keep AI systems under control. We could characterize her view as "fast" on 1a and 2a (because everything is happening so fast in wall clock time), "fast" on 1b (because of first-mover advantage), and "slow" on 2b (because we'll have lots of time to figure things out).
I...
I agree with the usefulness of splitting (1) vs. (2).
Question (2) is really a family of questions (how much time between <eventA> and needing to achieve <taskB> to avert doom?) And seems worth splitting those up too.
I also agree with splitting subjective vs. wall clock time, those are probably the ways I'd split it.
Just want to mention that this post caused me to update towards a continuous take-off. The humans and chimps section the most, as I hadn't noticed how much chimps weren't being optimised for general intelligence. And then the point that slow take-off means more change, sooner, was also key. I had been rounding slow take-off to a position which didn't really appreciate the true potential for capability gain, but your post showed me how to square that circle.
Fast take-off seems to me at the very least like a simplifying assumption, because I feel pretty unequipped to predict what will happen in the space before 'strongly superintelligent AGI' but after 'radical change due to AGI'. Would be interested to hear anyone's suggestions for reasoning about what that world will look like.
As additional data, I am grateful this post was written and found it to contain many good thoughts, but I updated away from continuous take-off due to conservation of evidence. I already knew Paul's basic view, and expected a post by him that had this level of thought and effort behind it to be more convincing than it was. Instead, I found my system-1 repeatedly not viewing the arguments as being convincingly answered or often really even understood as I understand them, my and Paul's model for what can accomplish what and the object-level steps that will get taken to get a takeoff seem super far apart and my instinctive reading of Paul's model doesn't seem plausible to me (which means I likely have it wrong), and I even saw pointers to some good arguments for fast takeoff I hadn't properly fully considered.
I especially found interesting that Paul doesn't intuitively grok the concept of things clicking. I am very much a person of the click. I am giving myself a task to add a post called Click to my draft folder.
Note that this comment is not intended to be an attempt to respond to the content, or to be convincing to anyone including Paul; I hope at some future date to write my thoughts up carefully in a way that might be convincing, or allow Paul or others to point out my mistakes (in addition to the click thing).
If people know my views they should update away half the time when they hear my arguments, so I guess I shouldn't be bummed (though hopefully that usually involves their impressions moving towards mine and their peer disagreement adjustment shrinking).
I'd love to read an articulation of the fast takeoff argument in a way that makes sense to me, and was making this post in part to elicit that. (One problem is that different people seem to have wildly different reasons for believing in fast takeoff.)
This is tangential, but I wanted to note that, a slow takeoff is, at least in some ways, a worse scenario than fast takeoff in terms of AI risk.
Designing an aligned AI (probably) involves trade-offs between safety and capability. In a fast takeoff scenario, the FAI "only" has to be capable enough to prevent UFAI from ever coming into being, in order for AI risk to be successfully mitigated. The most powerful potentially adversarial agents in its environment would be mere humans (and, yes, humans should be counted as somewhat adversarial since they are the source of the UFAI risk). In a (sufficiently) slow takeoff scenario, there will be a number of competing superintelligences, and it seems likely that at least some of them will not be aligned. This means that the FAIs have to be capable enough to effectively compete with UFAIs that are already deployed (while remaining safe).
Yes. I agree that neither scenario is strictly easier than the other. There are some plans that only work if takeoff is slow, and some plans that only work if takeoff is fast. Unfortunately, if you make the real world messier, I expect that neither of those categories is particularly likely to work well in practice. If you have a plan that works across several simple situations, then I think it's reasonable to hope it will work well in the (complicated) real situation. But if you have N plans, each of which works well in 1 of N simple situations, then you are liable to be overfitting.
Epistemics: Yes, it is sound. Not because of claims (they seem more like opinions to me), but because it is appropriately charitable to those that disagree with Paul, and tries hard to open up avenues of mutual understanding.
Valuable: Yes. It provides new third paradigms that bring clarity to people with different views. Very creative, good suggestions.
Should it be in the Best list?: No. It is from the middle of a conversation, and would be difficult to understand if you haven't read a lot about the 'Foom debate'.
Improved: The same concepts rewritten for a less-familiar audience would be valuable. Or at least with links to some of the background (definitions of AGI, detailed examples of what fast takeoff might look like and arguments for its plausibility).
Followup: More posts thoughtfully describing positions for and against, etc. Presumably these exist, but i personally have not read much of this discussion in the 2018-2019 era.
I imagine the "secret sauce" line of thinking as "we are solving certain problems in the wrong complexity class". Changing complexity class of an algorithm introduces a discontinuity; when near a take-off, then this discontinuity can get amplified into a fast take-off. The take-off can be especially fast if the compute hardware is already sufficient at the time of the break-through.
In other words: In order to expect a fast take-off, you only need to assume that the last crucial sub-problem for recursive self-improvement / explosion is done in the wrong complexity class prior to the discovery of a good algorithm.
For strong historical precedents, I would look for algorithmic advances that improved empirical average complexity class, and at the same time got a speed-up of e.g. 100 x on problem instances that were typical prior to the algorithmic discovery (so Strassen matrix-multiply is out).
For weaker historical precedent, I would look for advances that single-handedly made the entire field viable -- that is, prior to the advance one had a tiny community caring about the problem; post the advance, the field (e.g. type of data analysis) became viable at all (hence,...
For strong historical precedents, I would look for algorithmic advances that improved empirical average complexity class, and at the same time got a speed-up of e.g. 100 x on problem instances that were typical prior to the algorithmic discovery (so Strassen matrix-multiply is out).
Do you have any examples of this phenomenon in mind? I'm not aware of any examples with significant economic impact. If this phenomenon were common, it would probably change my view a lot. If it happened ever it would at least make me more sympathetic to the fast takeoff view and would change my view a bit.
Not sure. I encountered this once in my research, but the preprint is not out yet (alas, I'm pretty sure that this will still be not enough to reach commercial viability, so pretty niche and academic and not a very strong example).
Regarding "this is not common": Of course not for problems many people care about. Once you are in the almost-optimal class, there are no more giant-sized fruit to pick, so most problems will experience that large jumps never, once or twice over all of expected human history (sorting is even if you are a super-intelligence) (pulling the numbers 0,1,2 out of my ass; feel free to do better). On the other hand, there is a long tail of problems very few people care about (e.g. because we have no fast solution and hence cannot incorporate a solver into a bigger construction). There, complexity-class jumps do not appear to be so uncommon.
Cheap prediction: Many visual machine-learning algos will gain in complexity class once they can handle compressed data (under the usual assumption that, after ordering by magnitude, coefficients will decay like a power-law for suitable wavelet-transforms of real-world input data; the "compression&quo...
There seems to be a stronger version of the (pro-fast-takeoff) chimp vs human argument, namely average-IQ humans vs von Neumann: "IQ-100 humans have brains roughly the same size as von Neumann, but are much worse at making technology." Does your counterargument work against that version too? (I'm not sure I fully understand it.)
The argument in the post applies to within-human differences; it's a bit weaker, because evolution is closer to optimizing humans for technological aptitude than it is to optimizing chimps for technological aptitude.
Beyond that, what you infer from human variation depends a bit on where you see human variation as coming from:
I looked briefly into distribution of running speeds for kicks. Here is the distribution of completion times for a particular half-marathon, standard deviation is >10% of the total. Running time seems under more selection than scientific ability, but I don't know how it interacts with training and there are weird selection effects and so on.
For reference, if you think getting from "normal person" to von Neumann is as hard as making your car go 50% faster (4 standard deviations of human running speed in that graph), you might be interested in how long successive +50% improvements of the land speed record took:
Those numbers are way closer together than I expected, and now that the analogy appears to undermine my point it doesn't seem like a very good analogy to me, but it was a surprising fact so I feel like I should include it.
Not actually clear what you'd make of the analogy, even if you took it seriously. You could say that IT improves ~ an order of magnitude faster than industry, and scale down the time from ~8 years to ~0.8 years to go from normal to von Neumann. But no...
I like this post, but I think it's somewhat misleading to call your scenario a "slow takeoff". To my mind, a "slow takeoff" evokes an image from non-singularitarian science fiction where you have human-level robots running around and they've been running around for decades if not centuries: that is, a very slow and gradual development that gives society and institutions plenty of time to adapt. But your version is clearly not this, since you are talking on the timescale of a few years, and note yourself that time will be of the essence even with a "slow" takeoff:
If takeoff is slow: it will become quite obvious that AI is going to transform the world well before we kill ourselves, we will have some time to experiment with different approaches to safety, policy-makers will have time to understand and respond to AI, etc. But this process will take place over only a few years, and the world will be changing very quickly, so we could easily drop the ball unless we prepare in advance.
You also note that much of the safety community seems to believe in a fast takeoff, in disagreement with you. I don't know whether you're including me there...
In Superintelligence, Bostrom defines a "takeoff" as the transition "from human-level intelligence to superintelligence." This seems like a poor definition for several reasons: "human-level intelligence" is a bad concept, and "superintelligence" is ambiguous in Bostrom's book between "strong superintelligence" ("a level of intelligence vastly greater than contemporary humanity's combined intellectual wherewithal") and "[weak?] superintelligence" ("greatly [exceeding] the cognitive performance of [individual?] humans in virtually all domains of interest").
Moreover, neither of these thresholds is strategically important/relevant: "superintelligence" is too high and anthropocentric a bar for talking about seed AGI, and is too low a bar for talking about decisive strategic advantage; whereas "strong superintelligence" is just a really weird/arbitrary/confusing bar when the thing we care about is DSA.
More relevant thresholds on my view are things like "is it an AGI yet? can it, e.g., match the technical abilities of an average human engineer in at least one rich, messy real...
The place to situate the disagreement for mainstream skeptics of what Eliezer calls "rapid capability gain" might be something like: "Once we have AGI, is it more likely to take 2 subjective years to blow past human scientific reasoning in the way AlphaZero blew past human chess reasoning, or 10 subjective years?" I often phrase the MIRI position along the lines of "AGI destroys or saves the world within 5 years of being developed".
That's just talking in terms of widely held views in the field, though. I think that e.g. MIRI/Christiano disagreements are less about whether "months" versus "years" is the right timeframe, and more about things like: "Before we get AGI, will we have proto-AGI that's nearly as good as AGI in all strategically relevant capabilities?" And the MIRI/Hanson disagreements are maybe less about months vs. years and more about whether AGI will be a discrete software product invented at a particular time and place at all.
[Note that I am in no way an expert on strategy, probably not up to date with the discourse, and haven't thought this through. I also don't disagree with your conclusions much.]
[Also note that I have a mild feeling that you engage with a somewhat strawman version of the fast-takeoff line of reasoning, but have trouble articulating why that is the case. I'm not satisfied with what I write below either.]
These possible arguments seem not included in your list. (I don't necessarily think they are good arguments. Just mentioning whatever intuitively seems like it could come into play.)
Idiosyncrasy of recursion. There might be a qualitative difference between universality across economically-incentivized human-like domains, and universality extended to self-improvement from the point of view of a self-improving AI, rather than human-like work on AI. In this case recursive self-improvement looks more like a side effect than mainstream linear progress.
Actual secrecy. Some group might actually pull off being significantly ahead and protecting their information from leaking. There are incentives to do this. Related: Returns to non-scale. Some technologies might be easier ...
This post lead me to visualise the leadup to AGI more clearly, and changed how I talk about it in conversations. I think that while Paul's arguments were key, Ray's graph in the comments is the best summary of my main update. Also I think that the brief comments from Eliezer and Nate would be helpful if included.
I first interpreted your operationalization of slow take off to mean something that is true by definition (assuming the economy is strictly increasing).
I assume how you wanted me to interpret it is that the first 4 year doubling interval is disjoint from the first 1 year doubling interval. (the 4 year one ends before the 1 year one starts.)
I really liked this; despite its length, it's very readable, and helped move forward the discussion on this important topic with some simple ideas (to pick two: the graph was great, and the chimp argument seems to have surprised many people including me). For these reasons, I've curated this post.
(In future I would be happy to copy over the whole content of such a linked post, to encourage users to read the full arguments in detail. Let me know if there's any way we can help with that.)
I think this post is about an important point, but I notice myself wanting to nominate it more for Raemon's diagram that it sparked than Paul's post itself.
I think the arguments in this post have been one of the most important pieces of conceptual progress made in safety within the last few years, and have shifted a lot of people's opinions significantly.
...I believe that the disagreement is mostly about what happens before we build powerful AGI. I think that weaker AI systems will already have radically transformed the world, while I believe fast takeoff proponents think there are factors that makes weak AI systems radically less useful. This is strategically relevant because I'm imagining AGI strategies playing out in a world where everything is already going crazy, while other people are imagining AGI strategies playing out in a world that looks kind of like 2018 except that someone is about to get a decis
I just came here to point out that even nuclear weapons were a slow takeoff in terms of their impact on geopolitics and specific wars. American nuclear attacks on Hiroshima and Nagasaki were useful but not necessarily decisive in ending the war on Japan; some historians argue that the Russian invasion of Japanese-occupied Manchuria, the firebombing of Japanese cities with massive conventional bombers, and the ongoing starvation of the Japanese population due to an increasingly successful blockade were at least as influential in the Japanese decision to sur...
My thoughts on the "Humans vs. chimps" section (which I found confusing/unconvincing):
...Chimpanzees have brains only ~3x smaller than humans, but are much worse at making technology (or doing science, or accumulating culture…). If evolution were selecting primarily or in large part for technological aptitude, then the difference between chimps and humans would suggest that tripling compute and doing a tiny bit of additional fine-tuning can radically expand power, undermining the continuous change story.
But chimp evolution is not primarily selecting for makin
A few thoughts:
Updated me quite strongly towards continuous takeoff (from a position of ignorance). (I would also nominate the AI Impacts post, but I don't think it ever got cross-posted.)
Here's an argument why (at least somewhat) sudden takeoff is (at least somewhat) plausible.
Supposing:
(1) At some point P, AI will be as good as humans at AI programming (grandprogramming, great-grandprogramming, ...) by some reasonable standard, and less than a month later, a superintelligence will exist.
(2) Getting to point P requires AI R&D effort roughly comparable to total past AI R&D effort.
(3) In an economy growing quickly because of AI, AI R&D effort increases by at least the same factor as general economic growth.
Then:
(4) Based on ...
I expect "slow takeoff," which we could operationalize as the economy doubling over some 4 year interval before it doubles over any 1 year interval. Lots of people in the AI safety community have strongly opposing views, and it seems like a really important and intriguing disagreement. I feel like I don't really understand the fast takeoff view.
(Below is a short post copied from Facebook. The link contains a more substantive discussion. See also: AI impacts on the same topic.)
I believe that the disagreement is mostly about what happens before we build powerful AGI. I think that weaker AI systems will already have radically transformed the world, while I believe fast takeoff proponents think there are factors that makes weak AI systems radically less useful. This is strategically relevant because I'm imagining AGI strategies playing out in a world where everything is already going crazy, while other people are imagining AGI strategies playing out in a world that looks kind of like 2018 except that someone is about to get a decisive strategic advantage.
Here is my current take on the state of the argument:
The basic case for slow takeoff is: "it's easier to build a crappier version of something" + "a crappier AGI would have almost as big an impact." This basic argument seems to have a great historical track record, with nuclear weapons the biggest exception.
On the other side there are a bunch of arguments for fast takeoff, explaining why the case for slow takeoff doesn't work. If those arguments were anywhere near as strong as the arguments for "nukes will be discontinuous" I'd be pretty persuaded, but I don't yet find any of them convincing.
I think the best argument is the historical analogy to humans vs. chimps. If the "crappier AGI" was like a chimp, then it wouldn't be very useful and we'd probably see a fast takeoff. I think this is a weak analogy, because the discontinuous progress during evolution occurred on a metric that evolution wasn't really optimizing: groups of humans can radically outcompete groups of chimps, but (a) that's almost a flukey side-effect of the individual benefits that evolution is actually selecting on, (b) because evolution optimizes myopically, it doesn't bother to optimize chimps for things like "ability to make scientific progress" even if in fact that would ultimately improve chimp fitness. When we build AGI we will be optimizing the chimp-equivalent-AI for usefulness, and it will look nothing like an actual chimp (in fact it would almost certainly be enough to get a decisive strategic advantage if introduced to the world of 2018).
In the linked post I discuss a bunch of other arguments: people won't be trying to build AGI (I don't believe it), AGI depends on some secret sauce (why?), AGI will improve radically after crossing some universality threshold (I think we'll cross it way before AGI is transformative), understanding is inherently discontinuous (why?), AGI will be much faster to deploy than AI (but a crappier AGI will have an intermediate deployment time), AGI will recursively improve itself (but the crappier AGI will recursively improve itself more slowly), and scaling up a trained model will introduce a discontinuity (but before that someone will train a crappier model).
I think that I don't yet understand the core arguments/intuitions for fast takeoff, and in particular I suspect that they aren't on my list or aren't articulated correctly. I am very interested in getting a clearer understanding of the arguments or intuitions in favor of fast takeoff, and of where the relevant intuitions come from / why we should trust them.