It does look like most studies suggested small or no effects after less than 10 meters away, but I wonder how much they focused on eggs, larvae and zooplankton, which are plausibly more sensitive. For example, from this study (discussion):

Experimental air gun signal exposure decreased zooplankton abundance when compared with controls, as measured by sonar (~3–4 dB drop within 15–30 min) and net tows (median 64% decrease within 1 h), and caused a two- to threefold increase in dead adult and larval zooplankton. Impacts were observed out to the maximum 1.2 km range sampled, which was more than two orders of magnitude greater than the previously assumed impact range of 10 m. Although no adult krill were present, all larval krill were killed after air gun passage.

This might be an outlier study, though. I had Perplexity attempt a systematic review here.

I'd guess aquatic noise reduces populations across trophic levels. There's some evidence across different animal size groups. It also seems a priori more likely that smaller animals, like zooplankton, will have the largest population-relative direct effects at a given noise volume because the force will be larger relative to their body and organ sizes (but they may be closer or farther from noise sources), and since they feed other animals up the food chain, higher trophic levels would have less available food, too.

Speculating pretty wildly: maybe larger primarily herbivorous species would be least affected or could increase in populations due to reduced competition for food with smaller herbivores. That could actually mean increasing the average welfare of aquatic animals.

Figured I'd flag that it seems pretty likely to me that aquatic noise reduces populations (and unlikely that it increases them), both fish and invertebrates, by increasing mortality and reducing fertility. See this thread with Perplexity AI (I haven't carefully verified the accuracy, though). So, reducing aquatic noise increases wild animal populations in expectation, which is plausibly bad if their lives are bad on average. There could be tradeoffs with average welfare, but I'd be at best clueless about whether reducing aquatic noise is good or bad overall for aquatic animals in the near term.

I suspect we need to involve our criteria for defining and picking bracketings here.

In practice, I think it doesn't make sense to just bracket in the bad long-term effects or just bracket in the good ones. You might be able to carve out bracketings that include only bad (or only good) long-term effects and effects outweighed by them, but not all bad (or all good) long-term effects. But that will depend on the particulars.

I think if we only do spatiotemporal bracketing, it tells us to ignore the far future and causally inaccessible spacetime locations, because each such location is made neither determinately better off in expectation nor determinately worse off in expectation. I'm not entirely sure where the time cutoff should start in practice, but it would be related to AGI's arrival. That could make us neartermist.

But we may also want to bracket out possibilities, not just ST locations. Maybe we can bracket out AGI by date X, for various X (or the min probability of it across choices, in case we affect its probability), and focus on non-AGI outcomes we may be more clueful about. If we bracket out the right set of possibilities, maybe some longtermist interventions will look best.

My sense is that if you're weighing nematodes, you should also consider things like conscious subsystems or experience sizes that could tell you larger-brained animals have thousands or millions of times more valenced experiences or more valence at a time per individual organism. For example, if a nematode realizes some valence-generating function (or indicator) once with its ~302 neurons, how many times could a chicken brain, with ~200 million neurons, separately realize a similar function? What about a cow brain, with 3 billion neurons?

Taking expected values over those hypotheses and different possible scaling law hypotheses tends, on credences I find plausible, to lead to expected moral weights scaling roughly proportionally with the number of neurons (see the illustration in the conscious subsystems post). But nematodes (and other wild invertebrates) could still matter a lot even on proportional weighing, e.g. as you found here.

Ya, bracketing on its own wouldn’t tell you to ignore a potential group of moral patients just because its probability of sentience is very small. The numbers could compensate. It's more that conditional on sentience, we'd have to be clueless about whether they're made better or worse off. And we may often be in this position in practice.

I think you could still want some kind of difference-making view or bounded utility function used with bracketing, so that you can discount extreme overall downsides more than proportionally to their probability, along with extreme upsides. Or do something like Nicolausian discounting, i.e. ignoring small probabilities.

Great post! :)

Third, it’s easy for an org to think it’s helping when it’s hurting: we know so little about how to help that some caution is warranted. I don’t just want to do good in expectation: I want to do good.

FWIW, I think this would count against most animal interventions targeting vertebrates (welfare reforms, reductions in production), and possibly lead to paralysis pretty generally, and not just for animal advocates.

If we give extra weight to net harm over net benefits compared to inaction, as in typical difference-making views, I think most animal interventions targeting vertebrates will look worse than doing nothing, considering only the effects on Earth or in the next 20 years, say. This is because:

1. there are possibly far larger effects on wild invertebrates (even just wild insects and shrimp, but also of course also mites, springtails, nematodes and copepods) through land use change and effects on fishing, and huge net harm is possible through harming them, and
2. there's usually at least around as much reason to expect large net harm to wild animals as there is to expect large net benefit to them, and difference-making gives more weight to the former, so it will dominate.

There could be similar stories for the far future and acausally, replacing wild animals on Earth with far future moral patients and aliens. There are also possibilities and effects of which we're totally unaware.

That being said, I suspect typical accounts of difference-making lead to paralysis pretty generally for similar reasons. This isn't just a problem for animal interventions. I discussed this and proposed some alternative accounts here.

Bracketing can also sometimes help. It's an attempt to formalize the idea that when we're clueless about whether some group of moral patients is made better off or worse off, we can just ignore them and focus on those we are clueful about.

Sounds exciting!

Do you have an estimate of the cost of the product per rodent spared you can share? This could help set a lower bound on the potential cost-effectiveness, where in the roughly worst case, donors, grantmakers or impact investors buy or subsidize the product for snake owners, similar to SWP buying stunners for shrimp producers.

(Edited: had the comparison of sizes flipped.)

One thought I've just had about this: these "cumulative elasticities" assume demand/price shifts just for one product at a time, and will therefore be too (EDIT) low if used for the effects of people going veg or reducing their consumption of multiple animal products. Here's why:

1. Suppose one person (or a large group of them) just cuts out chicken, and for simplicity, they don't eat more of anything else to compensate. That reduces the price of chicken. Other people will eat more chicken and less of everything else (including other animal products) to compensate, all else (or at least elasticities) equal. All else equal, it will also disproportionately affect chicken production.
2. Now, suppose this same person (or same large group of people) go vegan. This reduces the price of all animal products. Instead of others consuming more chicken and less of everything else in response, they consume more animal products all around (all else equal) and less plant-based food. The effect of other consumers on chicken in particular will be smaller than in 1, because they aren't shifting away from other animal products to eat more chicken in particular. So more of the demand shift goes through.

It can also matter whether the elasticities were determined in a model with multiple products (general equilibrium), including with cross-price elasticities of demand, or just a single-product market. In models with multiple products, when you estimate the price elasticity of chicken demand, you're adjusting for other prices and quantities besides chicken's. In a model with just chicken prices and quantities, you aren't adjusting for other products' prices and quantities. These elasticities will differ.

Great post, thanks for writing!

I buy that individuals should try to pick "policies" and psychologically commit themselves to them, rather than only evaluate actions one at a time. I think this totally makes sense for seatbelts and helmets. However, I'm not sure it requires evaluating actions collectively at a fundamental normative level rather than practically, especially across individuals. I think we can defend wearing seatbelts and helmets with Nicolausian discounting without supporting longtermism or x-risk work to most individuals, even if the marginal x-risk opportunity were similar to the average or best already funded.

In particular, I know that if I don't wear my seatbelt this time in a car by some logic that is not very circumstance-specific, I could use similar logic in the future to keep talking myself out of wearing a seatbelt, and those risks would accumulate into a larger risk that could be above the discount threshold. So I should stop myself now to minimize that risk. I should consider the effects of my reasoning and decision now on my own future decisions.

However, I don't have nearly as much potential influence over humanity's x-risk strategy (causally or acausally) and the probability of an existential catastrophe. The typical individual has hardly any potential influence.

Also, separately, how would you decide who or what is included in the collective? Should we include the very agents creating the problems for us?