I'm pointing out what seem to me to be large and important holes in your argument.

To an objection of the form "You have given no good reason to think Y follows from X", it is not reasonable to respond with "You need to give a specific example of how you can have X and not Y, with realistic numbers in it".

I claim that you have given no reason to think that if there's a lot of good to be done at $5k per life-equivalent then there is necessarily an experiment that it's feasible for (say) GiveWell to conduct that would do something like eliminating all malaria deaths in Madagascar for a year. You've just said that obviously there must be.

I reject any norms that say that in that situation anyone saying that your reasoning has gaps in is obliged to show concrete counterexamples.

However, because I'm an obliging sort of chap, let's have a go at constructing one and see what happens. (But, for the avoidance of doubt, I am not conceding that if my specific counterexample turns out not to work then it means your claim is right and mine is wrong. Of course it's possible that you know ahead of time that I can't construct a working counterexample, on account of having a better understanding than mine of the situation -- but, again, in that case communicating that better understanding should be part of your argument.) I'll look at Madagascar since that's the country you mentioned specifically.

[EDITED to add:] Although the foregoing paragraph talks about "constructing a counterexample", in fact what I did in the following paragraphs is just to make some guesses about numbers and see where they lead; I wasn't trying to pick numbers that are maximally persuasive or anything.

So, first of all let's find some numbers. Madagascar has a population of about 26 million. Malaria is the 7th most common cause of death there. If I'm reading the stats correctly, about 10% of the population has malaria and they have about 6k deaths per year. Essentially the entire population is considered at risk. At present Madagascar gets about $50M/year of malaria-fighting from the rest of the world. Insecticide-treated bed nets allegedly reduce the risk of getting malaria by ~70% compared with not having them; it's not clear to me how that's defined, but let's suppose it's per year. The statistics I've seen differ somewhat in their estimates of what fraction of the Madagascan population has access to bed nets; e.g., in this document from the WHO plot E on page 85 seems to show only ~5% of the population with access to either bed nets or indoor spraying; the table on page 117 says 6%; but then another table on page 122 estimates ~80% of households have at least one net and ~44% have at least one per two people. I guess maybe most Madagascan households have a great many people? These figures are much lower in Madagascar than in most of Africa; I don't know why. It seems reasonable to guess that bed net charities expect it to be more expensive, more difficult or less effective in Madagascar than in the other places where they have distributed more nets, but again even if this is correct I don't know what the underlying reasons are. I observe that several African countries have a lot more malaria deaths per unit population; e.g., Niger has slightly fewer people than Madagascar but nearly 3x as many malaria deaths. (And also about 3x as many people with malaria.) So maybe bed net distribution focuses on those countries?

So, my first observation is that this is all consistent with the possbility that the number of lives saveable in Madagascar at ~$5k/life is zero, because of some combination of { lower prevalence of malaria, higher cost of distributing nets, lower effectiveness of nets } there compared with, say, Niger or the DRC. This seems like the simplest explanation of the fact that Madagascar has surprisingly few bed nets per person, and it seems consistent with the fact that, while it certainly has a severe malaria problem, it has substantially less malaria per person than many other African countries. Let's make a handwavy guess that the effectiveness per dollar of bednets in Madagascar is half what it is in the countries with the best effectiveness-per-dollar opportunities, which conditional on that $5k/life-equivalent figure would mean $10k/life-equivalent.

Now, as to fatality: evidently the huge majority of people with malaria do not die in any given year. (~2.5M cases, ~6k deaths.) Malaria is a serious disease even when it doesn't kill you. Back of envelope: suppose deaths from malaria in Madagascar cost 40 QALYs each (life expectancy in Madagascar is ~66y, many malaria deaths are of young children but not all, there's a lot of other disease in Madagascar and I guess quality of life is often poor, handwave handwave; 40 QALYs seems like the right ballpark) and suppose having malaria but not dying costs 0.05 QALYs per year (it puts you completely out of action some of the time, makes you feel ill a lot more of the time, causes mental distress, sometimes does lasting organ damage, etc.; again I'm making handwavy estimates). Then every year Madagascar loses ~125k QALYs to nonfatal malaria and ~240k QALYs to fatal malaria. Those numbers are super-inexact and all I'm really comfortable concluding here is that the two are comparable. I guess (though I don't know) that bednets are somewhere around equally effective in keeping adults and children from getting malaria, and that there isn't any correlation between preventability-by-bednet and severity in any particular case; so I expect the benefits of bednets in death-reduction and other-illness-reduction to, again, be comparable. I believe death, when it occurs, is commonly soon after infection, but the other effects commonly persist for a long time. I'm going to guess that 3/4 of the effects of a change in bednet use happen within ~ a year, with a long tail for the rest.

So, let's put that together a bit. Most of the population is not currently protected by bednets. If they suddenly were then we might expect a ~70% reduction in new malaria cases that year, for those protected by the nets. Best case, that might mean a ~70% reduction in malaria deaths that year; presumably the actual figure is a bit less because some malaria deaths happen longer after infection. Call it 60%. Reduction in malaria harm that year would be more like 50%. Cost would be $10k per life-equivalent saved. Total cost somewhere on the order of $50M, a substantial fraction of e.g. AMF's total assets.

Another way to estimate the cost: GiveWell estimates that AMF's bednet distribution costs somewhere around $4.50 per net. So one net per person in Madagascar is $100M or so.

But that's only ~60% of the deaths; you wanted a nice clear-cut experiment that got rid of all the malaria deaths in Madagascar for one year. And indeed cutting deaths by 60% would not necessarily be conclusive, because the annual variation in malaria cases in Madagascar seems to be large and so is the uncertainty in counting those cases. In the 2010-2017 period the point estimates in the document I linked above have been as low as ~2200 and as high as ~7300; the error bars each year go from just barely above zero to nearly twice the point estimate. (These uncertainties are much larger, incidentally, than in many other African countries with similar malaria rates, which seems consistent with there being something about Madagascar that makes treatment and/or measurement harder than other African countries.)

To get rid of all (or nearly all) the deaths in one year, presumably you need to eliminate infection that happens while people aren't sleeping under their bed nets, and to deal with whatever minority of people are unwilling or unable to use bed nets. Those seem like harder problems. I think countries that have eliminated malaria have done it by eliminating the mosquitoes that spread it, which is a great long-term solution if you can do it but much harder than distributing bed nets. So my best guess is that if you want to get rid of all the malaria, even for one year, you will have to spend an awful lot more per life-equivalent saved that year; I would be unsurprised by 10x as much, not that surprised by 100x, and not altogether astonished if it turned out that no one actually knows how to do it for any amount of money. It might still be worth it if the costs are large -- the future effects are large if you can eliminate malaria from a place permanently. (Which might be easier in Madagascar than in many other African countries, since it's an island.) But it puts the costs out of the range of "things existing EA charities could easily do to prove a point". And it's a Gates Foundation sort of project, not an AMF one, and indeed as I understand it the Gates Foundation is putting a lot of money into investigating ways to eliminate malaria.

Tentative conclusion: It's not a all obvious to me that this sort of experiment would be worth while. For "only" an amount of money comparable to the total assets of the Against Malaria Foundation, it looks like it might be possible to somewhat-more-than-halve malaria deaths in Madagascar for one year (and reduce ongoing malaria a bit in subsequent years). The expected benefits of doing this would be substantially less than those of distributing bed nets in the probably-more-cost-effective other places where organizations like AMF are currently putting them. Given how variable the prevalence of malaria is in Madagascar, and how uncertain the available estimates of that prevalence seem to be, it is not clear that doing this would be anything like conclusive evidence that bednet distribution is as effective as it's claimed to be. (All of the foregoing is conditional on the assumption that it is as effective as claimed.) To get such conclusive evidence, it would be necessary to do things radically different from, and probably far more expensive than, bednet distribution; organizations like AMF would have neither the expertise nor the resources to do that.

I am not very confident about any of the numbers above (other than "easy" ones like the population of Madagascar), and all my calculations are handwavy estimates (because there's little point doing anything more careful when the underlying numbers are so doubtful). But what those calculations suggest to me is that, whether or not doing the sort of experiment you propose would be a good idea, it doesn't seem to be an obviously good idea (since, in particular, my current best estimate is that it would not be a good idea). Therefore, unless I am shown compelling evidence pointing in a different direction, I cannot take seriously the claim that EA organizations that aren't doing such experiments show thereby that they don't believe that there is large scope for doing good at a price on the order of $5k per life-equivalent.

I can well believe that universities used to work well and worsened over time. The point of my question at the end there is that I would expect any New Improved University Replacement to suffer the same process.

(Of course it might be worth it anyway, if it works better for long enough.)

I agree that you can make a case that sending a lot of people to university is wasteful; maybe you can make a case that sending anyone to university is wasteful (though, for what it's worth, that feels entirely wrong to me). But shminux was making a different claim: that our universities are so wasteful that they imperil our civilization's survival. That claim seems absurdly overblown to me.

Yes, the age at which people go to university is a good age for learning new things. That would be why people of that age are often encouraged to go off to a place designed for learning new things: a university.

Maybe just getting a job will (on average) actually result in learning more valuable things, but frankly I don't see any reason to believe that. (More things valuable for becoming a cog in someone else's industrial machine, maybe, though even that isn't obvious.)

Maybe all young people (or at least all fairly bright young people?) should be trying to start their own businesses, but again I see no reason to believe that either. Starting a business is hard; most new businesses fail; most 18-year-olds lack knowledge and experience that would greatly improve their chances of starting a successful business. (There are other reasons why I think this would be a bad idea, but since I'm not even sure it's what you have in mind I'll leave it there.)

Maybe the learning people currently do at universities, or the learning they're meant to be doing at universities, or whatever other learning should replace it, should be done "in the background" while they are working a job; but I see no reason to think that's even possible in most cases. Their jobs are likely to be too demanding in time, effort and mental focus. For sure some people can do it, but if you want it to be the general case then I'd like to see evidence that it's feasible.

Maybe we need different ways of optimizing 18-20-year-olds' lives for learning new and valuable things. I'd be interested to see concrete proposals. An obvious question I hope they'd address: why expect that in practice this will end up better than universities?

So the usual story about Easter Island is that construction and transportation of the statues used up all their palm trees, and the island's ecosystem depended on the palm trees, so they starved to death or something. (I think there's some doubt about whether that's actually right, but it's a plausible enough story and a useful analogy even if it turns out not to be literally true.)

What resource are universities in danger of consuming all of?

Money? US spending on universities seems to be on the order of a couple of percent of GDP.

Researcher time? Even supposing that university research is worthless, there's a lot of research being done by corporate R&D departments, and OP here gives some examples to suggest that some of it's pretty good. (And, for what it's worth, I don't find it plausible that university research is worthless, though no doubt some of it is.)

Students' youth? Even supposing that time spent at university is worthless, it's only a few years per person. (And, for what it's worth, I don't find it plausible that time spent at university is worthless. I know that at university I both had fun and learned things I am still glad to know; maybe I was exceptionally lucky but I don't know of any good reason to think so.)

So I assume you're objecting to his statement near the end that "the estimate that you can save a life for $5000 remains probably true (with normal caveats about uncertainty)", on the basis that he should actually say "you probably can't really save a life for $5000 because if you give that $5000 then the actual result will be that Good Ventures gives less in future because GiveWell will make sure of that to ensure that alleged $5000 opportunities continue to exist for PR reasons".

But I don't see the alleged switching back and forth. So far as I can see, Scott simply disagrees with you about the intertemporal funging thing, perhaps for the same reason as I think I do (namely, that GiveWell's actual statements about their recommendations to Good Ventures specifically claim that they are trying to make them in a way that doesn't involve intertemporal funging of a sort that messes up incentives in the way you say it does).

Where do you think Scott's comment assumes the "steep diminishing returns story"?

It does tell a steep-diminishing-returns story about the specific idea of trying to run the sort of experiment you propose. But part of his point is that that sort of experiment would likely be inefficient and impractical, unlike just continuing to do what AMF and similar charities are already doing with whatever funding is available to them. The diminishing returns are different in the two scenarios, and it could be that they are much steeper if you decide that your goal is to eliminate all malaria deaths on Madagascar than if your goal is to reduce malaria in all the areas where there's a lot of malaria that can be addressed via bed nets. It can simultaneously be true that (1) there are readily available opportunities to save more than 6k extra lives by distributing more bed nets, at a cost of $5k per life saved, and that (2) if instead you want to save specifically all 6k people who would otherwise have died from malaria in Madagascar this year, then it will cost hugely more than $5k per life. And also, relatedly, that (3) if instead of this vague "you" we start trying to be specific about who is going to do the thing, then in case 1 the answer is that AMF can save those lives by distributing bed nets, a specific thing that it knows how to do well, whereas in case 2 the answer is that there is no organization that has all the competences required to save all those lives at once, and that making it happen would require a tremendous feat of coordination.

It's a bit like the difference between "Ben thinks Gareth is giving too much money to the Against Malaria Foundation" and "Ben thinks Gareth isn't letting enough babies die of malaria", in the context of a discussion about how individuals should allocate their money.

I think you have the burden of proof in the wrong place. You are claiming that if there's a lot of good to be done at $5k then there must be experiments that are obviously worth pouring a lot of resources into. I'm simply saying that that's far from clear, for the reasons I gave. If it turns out that actually further details of the situation are such as to mean that there must be good experiments to do, then your argument needs to appeal to those further details and explain how they lead to that conclusion.

I am not making any specific claim about what fraction of malaria deaths are from infection in prior years, or what proportion can be prevented at ~$5k per life-equivalent, etc. To whatever extent those are relevant to the correctness of your claim that EA organizations would be running the sort of experiments you propose if they really believed their numbers, your argument for that claim should already be in terms of those figures.

I'm seeing a lot of replies saying, in effect, "duh, obviously #1: we only bother thinking about the questions whose answers are still somewhat open to doubt". Maybe that's the whole story, but I still don't think so: some questions remain in the category of "questions many people think about and aren't close to certain of the answers to" even as a lot of evidence accumulates.

(But maybe #1 is more of the story than I was inclined to think.)

Can you suggest a better way of framing the question?

(I'm not very sure what sort of adding-up-to-normality you have in mind; are you saying my "good explanation #1" is likely the correct one?)

I think probably Penrose's "The Road to Reality" was intended. I don't think there's anything in the Deutsch book like "curvature of spacetime is determined by infinitesimal light cones"; I don't think I've read the relevant bits of the Penrose but it seems like exactly the sort of thing that would be in it.