Researcher @ Longview Philanthropy
2779 karmaJoined Working (0-5 years)Oxford, UK


I do research at Longview Philanthropy. Previously I was a Research scholar at FHI and assistant to Toby Ord. Philosophy at Cambridge before that.

I also do a podcast about EA called Hear This Idea.


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Just I want to register the worry that the way you've operationalised “EA priority” might not line up with a natural reading of the question. 

The footnote on “EA priority” says:

By “EA priority” I mean that 5% of (unrestricted, i.e. open to EA-style cause prioritisation) talent and 5% of (unrestricted, i.e. open to EA-style cause prioritisation) funding should be allocated to this cause.

This is a bit ambiguous (in particular, over what timescale), but if it means something like “over the next year” then that would mean finding ways to spend ≈$10 million on AI welfare by the end of 2025, which you might think is just practically very hard to do even if you thought that more work on current margins is highly valuable. Similar things could have been said for e.g. pandemic prevention or AI governance in the early days!

Nice post! Copying the comment I left on the draft (edited for clarity) —

I agree with both conclusions, but I don't think your argument is the strongest reason to buy those conclusions.

My picture of how large-scale space expansion goes involves probes (not humans) being sent out after AGI. Then a reasonable default might be that the plans and values embedded in humanity's first large-scale space settlement initiatives are set by the plans and values of some very large and technologically advanced political faction at the time (capable of launching such a significant initiative by force or unanimity), rather than a smaller number of humans who were early to settle some part of the Solar System.

I then picture most human-originating life to not resemble biological humans (more like digital people). In this case it's very hard to imagine how farming animals would make any sense.

Even with shorter-term and human-led space settlement, like bases on the Moon and Mars, I expect it to make very little logistical sense to farm animals (regardless of the psychological profile of whoever is doing the settlement). The first settlements will be water and space and especially labour constrained, and raising animals is going to look needlessly painful and inefficient without the big economies of scale of factory farms. 

That said, if animals are farmed in early settlements, then note that smaller animals tend to be the most efficient at converting feed into human-palatable calories (and also the most space-efficient). For that reason some people suggest insect farming (e.g. crickets, mealworms), which does seem much more likely than livestock or poultry! But another option is bioreactors of the kind being developed on Earth. In theory they could become more efficient than animals and would then make most practical sense (since the capital cost to build the reactor isn't going to matter; taking anything into space is already crazy expensive). Also a lot of food will probably be imported as payload early on; unsure if that's relevant.

So I think I'm saying the cultural attitudes of early space settlers is probably less important than the practical mechanisms by which most of space is eventually settled. Especially if most future people are not biological humans, which kind of moots the question.

I do think it's valuable and somewhat relieving to point out that animal farming could plausibly remain an Earth-only problem!


I endorse many (more) people focusing on x-risk and it is a motivation and focus of mine; I don't endorse “we should act confidently as if x-risk is the overwhelmingly most important thing”.

Honestly, I think the explicitness of my points misrepresents what it really feels like to form a view on this, which is to engage with lots of arguments and see what my gut says at the end. My gut is moved by the idea of existential risk reduction as a central priority, and it feels uncomfortable being fanatical about it and suggesting others do the same. But it struggles to credit particular reasons for that.

To actually answer the question: (6), (5), and (8) stand out, and feel connected.


In this spirit, here are some x-risk sceptical thoughts:

  1. You could reasonably think human extinction this century is very unlikely. One way to reach this conclusion is simply to work through the most plausible causes of human extinction, and reach low odds for each. Vasco Grilo does this for (great power) conflict and nuclear winter, John Halstead suggests extinction risk from extreme climate change is very low here, and the background rate of extinction from natural sources can be bounded by (among other things) observing how long humans have already been around for. That leaves extinction risk from AI and (AI-enabled) engineered pandemics, where discussion is more scattered and inconclusive. Here and here are some reasons for scepticism about AI existential risk.
    • Even if the arguments for AI x-risk are sound, then it's not clear how they are arguments for expecting literal human extinction over outcomes like ‘takeover’ or ‘disempowerment’. It's hard to see why AI takeover would lead to smouldering ruins, versus continued activity and ‘life’, just a version not guided by humans or their values.
  2. So “existential catastrophe” probably shouldn't just mean "human extinction". But then it surprisingly slippery as a concept. Existential risk is the risk of existential catastrophe, but it's difficult to give a neat and intuitive definition of “existential catastrophe” such that “minimise existential catastrophe” is a very strong guide for how to do good. Hilary Greaves dicusses candidate definitions here.
  3. From (1), you might think that if x-risk reduction this century should be a near-top priority, then most its importance comes from mitigating non-extinction catastrophes, like irreversible dystopias. But few current efforts are explicitly framed as ways to avoid dystopian outcomes, and it's less clear how to do that. Other than preventing AI disempowerment or takeover, assuming those things are dystopian.
  4. But then isn't x-risk work basically just about AI, and maybe also biorisk? Shouldn't specific arguments for those risks and ways to prevent them therefore matter more than more abstract arguments for the value of mitigating existential risks in general? 
  5. Many strategies to mitigate x-risks trade off uncomfortably against other goods. Of course they require money and talent, but it's hard to argue the world is spending too much on e.g. preventing engineered pandemics. But (to give a random example), mitigating x-risk from AI might require strong AI control measures. If we also end up thinking things like AI autonomy matter, that could be an uncomfortable (if worthwhile) price to pay.
  6. It's not obvious that efforts to improve prospects for the long-run future should focus on preventing unrecoverable disasters. There is a strong preemptive argument for this; roughly that humans are likely to recover from less severe disasters, and so retain most their prospects (minus the cost of recovering, which is assumed to be small in terms of humanity's entire future). The picture here is one on which the value of the future is roughly bimodal — either we mess up irrecoverable and achieve close to zero of our potential, or we reach roughly our full potential. But that bimodal picture isn't obviously true. It might be comparably important to find ways to turn a mediocre-by-default future into a really great future, for instance.
    • A related picture that “existential catastrophe” suggests is that the causes of losing all our potential are fast and discrete events (bangs) rather than gradual processes (whimpers). But why are bangs more likely than whimpers? (See e.g. “you get what you measure” here).
  7. Arguments for prioritising x-risk mitigation often involve mistakes, like strong ‘time of perils’ assumptions and apples to oranges comparisons. A naive case for prioritising x-risk mitigation might go like this: “reducing x-risk this century by 1 percentage point is worth one percentage point of the expected value of the entire future conditional on no existential catastrophes. And the entire future is huge, it's like  lives. So reducing x-risk by even a tiny fraction, say , this century saves  (a huge number of) lives in expectation. The same resources going to any work directed at saving lives within this century cannot save such a huge number of lives in expectation even if it saved 10 billion people.” This is too naive for a couple reasons:
    • This assumes this century is the only time where an existential catastrophe could occur. Better would be “the expected value of the entire future conditional on no existential catastrophe this century”, which could be much lower.
    • This compares long-run effects with short-run effects without attempting to evaluate the long-run effects of interventions not deliberately targeted at reducing existential catastrophe this century.
  8. Naive analysis of the value of reducing existential catastrophe also doesn't account for ‘which world gets saved’. This feels especially relevant when assessing the value of preventing human extinction, where you might expect the worlds where extinction-preventing interventions succeed in preventing extinction are far less valuable than the expected value of the world conditional on no extinction (since narrowly avoiding extinction is bad news about the value of the rest of the future). Vasco Grilo explores this line of thinking here, and I suggest some extra thoughts here.
  9. The fact that some existential problems (e.g. AI alignment) seem, on our best guess, just about solvable with an extra push from x-risk motivated people doesn't itself say much about the chance that x-risk motivated people make the difference in solving those problems (if we're very uncertain about how difficult the problems are). Here are some thoughts about that.

These thoughts make me hesitant about confidently acting as if x-risk is overwhelmingly important, even compared to other potential ways to improve the long-run future, or other framings on the importance of helping navigate the transition to very powerful AI.

But I still existential risk matters greatly as an action-guiding idea. I like this snippet from the FAQ page for The Precipice

But for most purposes there is no need to debate which of these noble tasks is the most important—the key point is just that safeguarding humanity’s longterm potential is up there among the very most important priorities of our time.

[Edited a bit for clarity after posting]

Thanks for the comment, Owen.

I agree with your first point and I should have mentioned it.

On your second point, I am assuming that ‘solving’ the problem means solving it by a date, or before some other event (since there's no time in my model). But I agree this is often going to be the right way to think, and a case where the value of working on a problem with increasing resources can be smooth, even under certainty.

Ah thanks, good spot. You're right.

Another way to express (to avoid a stacked fraction) is ; i.e. percentage change in resources. I'll update the post to reflect this.

Just noticed I missed the deadline — will you be accepting late entries?

Edit: I had not in fact missed the deadline

Here's a framing which I think captures some (certainly not all) of what you're saying. Imagine graphing out percentiles for your credence distribution over values the entire future can take. We can consider the effect that extinction mitigation has on the overall distribution, and the change in expected value which the mitigation has. In the diagrams below, the shaded area represents the difference made by extinction migitation.

The closest thing to a ‘classic’ story in my head looks like below: on which (i) the long-run future is basically biomodal, between ruin and near-best futures, and (ii) the main effect of extinction mitigation is to make near-best futures more likely.

A rough analogy: you are a healthy and othrewise cautious 22-year old, but you find yourself trapped on a desert island. You know the only means of survival is a perilous week-long journey on your life raft to the nearest port, but you think there is a good chance you don't survive the journey. Supposing you make the journey alive, then your distribution over your expected lifespan from this point (ignoring the possibility of natural lifespan enhancement) basically just shifts to the left as above (though with negligible weight on living <1 year from now).

A possibility you raise is that the main effect of preventing extinction is only to make worlds more likely which are already close to zero value, as below. 

A variant on this possibility is that, if you knew some option to prevent human extinction were to be taken, your new distribution would place less weight on near-zero futures, but less weight on the best futures also. So your intervention affects many percentiles of your distribution, in a way which could make the net effect unclear.

One reason might be causal: the means required to prevent extinction might themselves seal off the best futures. In a variant of the shipwreck example, you could imagine facing the choice between making the perilous week-long journey, or waiting it out for a ship to find you in 2 months. Suppose you were confident that, if you wait it out, you will be found alive, but at the cost of reducing your overall life expectancy (maybe because of long-run health effects).

The above possibilities (i) assume that your distribution over the value of the future is roughly bimodal, and (ii) ignore worse-than-zero outcomes. If we instead assume a smooth distribution, and include some possibility of worse-than-zero worlds, we can ask what effect mitigating extinction has.

Here's one possibility: the fraction of your distribution that effectively zero value worlds gets is ‘pinched’, giving more weight both to better-than-zero worlds, and worse-than-zero worlds. Here you'd need to explain why this is a good thing to do.

So an obvious question here is how likely it is that extinction mitigation is more like the ‘knife-edge’ scenario of a healthy person trapped in a survive-or-die predicament. I agree that the ‘classic’ picture of the value of extinction mitigation can mislead about how obvious this is for a bunch of reasons. Though (as other commenters seem to have pointed out) it's unclear how much to rely on relatively uninformed priors, versus the predicament we seem to find ourselves in when we look at the world.

I'll also add that, in the case of AI risk, I think that framing literal human extinction as the main test of whether the future will be good seems like a mistake, in particular because I think literal human extinction is much less likely than worlds where things go badly for other reasons.

Curious for thoughts, and caveat that I read this post quickly and mostly haven't read the comments.

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