Thanks for the clarifying comment, Verónica. I strongly upvoted it. I would be happy to have a look into the CEAs of the animal welfare interventions (for free, sometime over the next 14 days or so). I just requested commenter access.

I found this very funny! Thanks for the post, Niki.

Hi Aaron and Will. I estimated how much cage-free corporate campaigns for layers, and the Shrimp Welfare Project’s (SWP’s) Humane Slaughter Initiative (HSI) increase the welfare of their target beneficiaries for individual welfare per fully-healthy-animal-year proportional to "individual number of neurons"^"exponent", and "exponent" from 0 to 2, which covers the best guesses that I consider reasonable. An exponent of 1 would correspond to the linear weighting preferred by Will. Below is a graph with the results. I calculate cage-free corporate campaigns increase the welfare of chickens more cost-effectively than HSI has increased the welfare of shrimps for an exponent of at least 0.94. For exponents of 0 and 2, cage-free corporate campaigns increase the welfare of chickens 6.71*10^-4 and 4.43 k times as cost-effectively as HSI has increased the welfare of shrimps.

The above only looks into effects on the target benefeciaries. However, I believe effects on soil animals resulting from changes in land use can easily dominate, as illustrated below. I assume that increasing agricultural land increases the welfare of soil animals, but I have very little idea about whether this is the case. So "Increase in the welfare" in the title of the graph should be read as "Absolute value of the change in the welfare". The graph does not look into HSI (electrically stunning shrimp), but I also do not know whether this increases or decreases welfare in expectation due to potentially dominant effects on soil animals and microorganisms.

Hi Charlie. I agree it is better to target soil animals instead of farmed shrimps if individual welfare is proportional to the individual number of neurons as suggested by @William_MacAskill. Here are my estimates for the total number of neurons of animal populations. I calculate soil nematodes have 5.93 M times as many neurons in total as farmed shrimps.

It is also worth noting that only wild finfishes and soil animals have more neurons in total than humans.

As a fun fact, @Ajeya was early to the potential importance of nematodes. In her biological anchors report about transformative AI (TAI) timelines, she calculated the compute performed by evolution considering just nematodes.

Ajeya estimates 10^41. I [Scott Alexander] can’t believe I’m writing this. I can’t believe someone actually estimated the number of floating point operations involved in jellyfish rising out of the primordial ooze and eventually becoming fish and lizards and mammals and so on all the way to the Ascent of Man. Still, the idea is simple. You estimate how long animals with neurons have been around for (10^16 seconds), total number of animals at any given second (10^20) times average number of FLOPS per animal (10^5) and you can read more here but it comes out to 10^41 FLOs. I would not call this an exact estimate - for one thing, it assumes that all animals are nematodes, on the grounds that non-nematode animals are basically a rounding error in the grand scheme of things [emphasis mine].

Hi Laura.

Spending on corporate cage-free campaigns for egg-laying hens is robustly^[8] cost-effective under nearly all reasonable types and levels of risk aversion considered here.

[...]

I am only considering the first-order cost-effectiveness of the interventions, whereas it is likely there are externalities (potentially both positive and negative) to spending on each intervention [more].

Do you have any thoughts on how accounting for effects on soil animals on change your conclusions? I have very little idea about whether cage-free campaigns for egg-laying hens increases or decreases animal welfare accounting for effects on ants and termites.

Thanks for sharing, Verónica. The cost-effectiveness analyses (CEAs) were done by Claude, right? How much did you review them?

Agreed, Tom. Here is a related post from Kevin Xia.

Thanks for clarifying, Mal.

How much more optimistic would you be about research on i) the welfare of soil animals and microorganisms, and ii) comparisons of (expected hedonistic) welfare across species if you strongly endorsed expectational total hedonistic utilitarianism, moral realism, and precise probabilitites, and ignored acausal effects, and effects after 100 years?

Based on age-structured mortality models for affected species like song sparrows, collision victims who survive gain approximately 1–2 additional years of life

Do you mean the life expectancy of birds who would avoid collisions thanks to bird-safe glass would increase by 1 to 2 years? I assume collision victims who survive have a lower life expectancy than birds who avoid collisions thanks to the bird-safe glass. @Luke Hecht may have thoughts on this.