We [propose to] use the euthanasia guidelines that veterinarians have developed for companion animals to assess whether it would be appropriate to recommend euthanization at various life stages. If so, that suggests that chickens’ lives are no longer worth living at that life stage. And if those life stages make up the bulk of the life, that’s some evidence that their lives are net negative on the whole.

I assume most vets only recommend euthanasia for pets whose future welfare they expect to be negative. I think the owners of pets would likely prefer to keep them alive even if they had slightly negative lives. Likewise, I believe people prefer their family members to remain alive if they have slightly negative lives. So I infer vets recommending euthanasia for pet chickens living in the conditions of farmed chickens would be significant evidence that farmed chickens have negative lives. On the other hand, I would say vets not recommending that would be very little evidence that farmed chickens have positive lives. I wonder whether your project would be very likely to produce inconclusive results due to vets being very unlikely to recommend that.

Have you considered asking random people, or people with chronic pain who regularly experience disabling pain about how they trade-off the Welfare Footprint Institute's (WFI's) pain and pleasure categories? Ambitious Impact's (AIM's) estimates for suffering-adjusted days (SADs) rely on pain intensities calculated with a weighted geometric mean with weight of 55 % on answers from 77 people. These were surveyed by AIM or @saulius, or shared their pain intensities on EA Forum. You can ask Vicky Cox for the sheet. The respondents are quite connected to the EA community, and I guess only a few (if any) have chronic pain, and regularly experience disabling pain. Your surveys and data analysis team could get a representative sample of the whole population of a given country, or focus on people people with chronic pain who regularly experience disabling pain. The answers would be useful to assess any intervention (regardless of the species), not just whether chickens have positive or negative lives. I expect the answers would vary a lot by person, but I would still be interested to know which fraction of people have pain and pleasure intensities which result in positive or negative lives for chickens (in particular, layers in enriched cages and barns, and broilers of a typical fast and slow growth breed).

Alternatively, you could ask people with chronic pain who regularly experience disabling pain how many hours per day of annoying, hurtful, disabling, and excruciating pain, satisfaction, joy, euphoria, and bliss they experience, and whether they would prefer not having been born neglecting effects on others. The answers could be used to predict which fraction of people prefer not having been born neglecting effects on others based on how many hours per day they experience WFI's pain and pleasure categories. I believe explicitly asking about when people prefer not having been born neglecting effects on others is a more robust way of assessing whether their lives are positive or negative. In the survey above, this is determined only indirectly via their preferences. On the other hand, the survey above would be useful to assess any intervention in a scope-sensitive way, as it would allow the measurement of welfare in a ratio scale.

You are welcome! I only posted the comment here to avoid having to keep 2 threads updated. You may consider linking to your EA Forum crossposts at the start of your substack posts.

I will write more on the Welfare Ranges project later

Good to know!

I am quite skeptical of neural counts as a proxy for welfare ranges

Are you sceptical of welfare ranges being proportional to "individual number of neurons"^"exponent"? I think it makes a lot of sense that one is spectical of any particular exponent. For example, of welfare ranges being proportional to the individual number of neurons, which corresponds to an exponent of 1. However, being sceptical about any exponent requires much more confidence. For instance, it would require being sceptical of the welfare ranges presented in Bob's book, which are pretty well explained by an exponent of 0.188 (see 1st graphs in my last comment).

You are welcome! Rethink Priorities (RP) has a research agenda on valuing impacts across species, and Hannah Tookey from RP commented the following on 6 January 2026. “We don’t currently have anything scheduled on this topic [“projects decreasing the uncertainty of interspecies comparisons of expected hedonistic welfare”], but we regularly review project ideas and may consider working on something like this a little later in the year. Dedicated funding would certainly make it more likely that we could prioritize this work”.

Thanks for the context, Jamie! That makes sense to me. I would still be curious to know about concrete decisions that were significantly influenced by the Pulse project. Its impact seems less tangible to me than that of RP's research targeting particular cause areas. However, this could easily be because I am less familiar with movement building efforts.

I [Jim] think maybe we should be more uncertain about inter-species tradeoffs than you seem to be, here.

I agree I have underestimated the uncertainty in comparisons between the individual (expected hedonistic) welfare per unit time of different species. I now recommend decreasing this uncertainty.

I continue to recommend funding the Centre for Exploratory Altruism Research’s (CEARCH’s) High Impact Philanthropy Fund (HIPF), which I estimate decreases 5.07 billion soil-animal-years per $. I recommend even more investigating whether soil nematodes have positive or negative lives.

After the post above, I recommended research informing how to increase the welfare of soil animals (for example, my top recommendation quoted above) over pursuing whatever land use change interventions naively seem to achieve that the most cost-effectively. I have little idea about whether funding HIPF (as recommended in the 1st sentence quoted above), or any other way of changing land use increases or decreases welfare. I am very uncertain about what increases or decreases soil-animal-years, and whether soil animals have positive or negative lives.

I currently recommend decreasing the uncertainty about how the (expected hedonistic) welfare per unit time of different organisms and digital systems compares with that of humans. I am now more pessimistic about research informing how to increase the welfare of soil animals. I have very little idea about whether existing interventions which robustly increase the welfare of humans or non-soil animals increase or decrease animal welfare due to potentially dominant uncertain effects on soil animals. Likewise, I do not know whether hypothetical interventions which robustly increased the welfare of soil animals would increase or decrease welfare due to potentially dominant uncertain effects on soil microorganisms.

I recommend research informing how to increase the welfare of soil animals over pursuing whatever land use change interventions naively seem to achieve that the most cost-effectively.

I currently recommend decreasing the uncertainty about how the (expected hedonistic) welfare per unit time of different organisms and digital systems compares with that of humans. I am now more pessimistic about the above. I have very little idea about whether existing interventions which robustly increase the welfare of humans or non-soil animals increase or decrease animal welfare due to potentially dominant uncertain effects on soil animals. Likewise, I do not know whether hypothetical interventions which robustly increased the welfare of soil animals would increase or decrease welfare due to potentially dominant uncertain effects on soil microorganisms.

I have also estimated the total welfare of animal populations, trees, and bacteria and archaea assuming individual (expected hedonistic) welfare per fully-happy-organism-year is proportional to "metabolic energy consumption per unit time at rest at 25 ºC"^"exponent". I had recommended research informing how to increase the welfare of soil animals, but I am now more pessimistic about this. I currently think it is better to focus on decreasing the uncertainty about how the individual welfare per unit time of different organisms and digital systems compares with that of humans.

You are welcome! I have now estimated the total welfare of animal populations, trees, and bacteria and archaea assuming individual welfare per fully-healthy-organism-year is proportional to "metabolic energy consumption per unit time at rest"^"exponent". I had recommended research informing how to increase the welfare of soil animals, but I am now more pessimistic about this. I currently think it is better to focus on decreasing the uncertainty about how the individual welfare per unit time of different organisms and digital systems compares with that of humans.

Relatedly, here is an illustration of why I think individual welfare per fully-healthy-animal-year could be proportional to "metabolic energy consumption per unit time at rest"^"exponent".

I have now estimated the total welfare of animal populations, trees, and bacteria and archaea based on the assumption above. I had recommended research informing how to increase the welfare of soil animals, but I am now more pessimistic about this. I currently think it is better to focus on decreasing the uncertainty about how the welfare per unit time of different organisms and digital systems compares with that of humans.