Hi Nick. Fair point. I thought about those effects, but should have explained why I did not cover them in the post. I have now added the following to the summary and main text.

I have not considered the effects of my vaccination on other people, soil animals, or microorganisms, but they do not change my decision. I think they are much smaller than the effects on my work and donations resulting from the time and monetary costs of my vaccination.

My marginal earnings go towards donations, and I believe donating the difference between my estimates for the cost and benefits of 24.7 $ to the most cost-effective global health interventions would increase human welfare more than the benefits of my vaccination to other people. GiveWell published a report on dietary salt modification in July 2025 where they concluded the following.

Overall, we estimate that it costs about $855 to avert a death via dietary salt modification in China and India, and the intervention is about 14 times as cost-effective as spending on unconditional cash transfers. However, this is a preliminary estimate that we plan to refine with additional work.

According to Coefficient Giving (CG), “GiveWell uses moral weights for child deaths that would be consistent with assuming 51 years of foregone life in the DALY framework (though that is not how they reach the conclusion)”. Assuming 51 DALY/life, the above cost-effectiveness would be 0.0596 DALY/$ (= 51/855). So 24.7 $ would avert 1.47 DALYs (= 24.7*0.0596). Supposing 1 DALY/symptomatic-flu-year, which greatly overestimate the badness of having a symptomatic flu, my vaccination would only be worth it if it averted more than 1.47 symptomatic-flu-years (= 1.47/1) in other people, or 97.6 symptomatic flus (= 1.47/(5.50/365.25)) for my assumption of 5.50 days of symptoms per symptomatic flu.

The benefits to other people would only materialise in cases where the vaccination prevented me from getting a symptomatic flu, which is when I could have infected other people. Combining the above with my assumption of "0.0610 symptomatic flus per person-year", I estimate I would have to have infected 1.60 k (= 97.6/0.0610) people conditional on getting a symptomatic flu for my vaccination to be worth it. In contrast, I would only contact with a few people if I had a symptomatic flu.

I believe I should consider effects not only on other people, but also on all potential beings. I suspect effects on soil animals and microorganisms are the driver of the overall effect, and I have very little idea whether their welfare would be increased or decreased. In any case, I think the conclusion accounting for all beings would still be that I should optimise for increasing the impact from my work and donations, which points towards my vaccination not being worth it.

Thanks for the follow-up, Whitney! I strongly upvoted it.

RE: The number of broiler chickens raised in China annually:

I have shared the estimates you provided with one person from the FAO.

https://www.stats.gov.cn/sj/sjjd/202501/t20250117_1958344.html/

Nitpick. "/" at the end has to be removed for the link to work.

6.5 billion egg-laying hens are in cages each year globally

This implies 23.0 % (= 1 - 6.5*10^9/(8.44*10^9)) of all laying hens outside cages assuming 8.44 billion laying hens as reported by FAO. I believe this fraction is too high. How did you get the 6.5 billion laying hens in cages globally? Do you think there are more than 8.44 billion laying hens globally?

any way you cut it it [broilers in cages] is a very major problem

Makes sense!

Thanks for the update, Nuno and Rai! I read the summary of weekly brief every week.

The last 10 M should be 1 M?

Thanks for the video, Nia! I liked it.

How different is that from ranking the results from RP's cross-cause cost-effectiveness model (CCM)? I collected estimates from this in a comment 2 years ago.

Similar to the answer about pain intensities, we’re trialing this in our cost-effectiveness models (though we are using the full range of the RP welfare capacity placeholder estimates, not just the median).

Note Rethink Priorities (RP) now only stands behind what is in Bob Fischer's book about comparing welfare across species, and its welfare ranges are different from the ones RP initially presented.

Sure!

Thanks, Aaron!

My intuitions around how to think about these animals currently seem to generally align with Bob Fischer’s thoughts.

You may be interested in my discussion of the above with Bob.

the animal movement needs to be thought about as an ecosystem, rather than a single org

I very much agree not all resources should go to the organisation with the current highest marginal cost-effectiveness, as this decreases with funding. However, my worry is not just that the best interventions are underfunded. It is that the current ecosystem is pursuing interventions which can easily be better or worse than, for example, burning money, or buying beef. I do not know about any interventions which robustly increase animal welfare due to potentially dominant uncertain effects on soil animals. I believe the ecosystem should optimise much more to decrease uncertainty about interspecies hedonistic welfare comparisons, and effects on soil animals and microorganisms.

Thanks for sharing!

What you would do to decrease the uncertainty about interspecies comparisons of expected hedonistic welfare as much as possible with 1 k, 10 k, 100 k, 1 M, and 10 M$? The picks should account not only for the outcomes of the research which was directly funded, but also for any additional research that is done to decrease the uncertainty further (supported by other funds).

I think Ambitious Impact (AIM), Animal Charity Evaluators (ACE), and the Animal Welfare Fund (AWF) use the welfare ranges initially presented by Rethink Priorities (RP), or the ones in Bob's book as if they are within a factor of 10 of the right estimates (such that these could 10 % to 10 times as large). However, I believe the differences could be much larger. For example, the estimate in Bob's book for the welfare range of shrimps is 8.0 % that of humans, but I would say it would be quite reasonable for someone to have a best guess of 10^-6, the ratio between the number of neurons of shrimps and humans.

Thanks for the post, Jeff!

At a floated $300B valuation and many EAs among their early employees, the amount of additional funding could be in the billions. [...]

One way to get a sense of the impact of donating sooner is to imagine that others will donate $1M to my preferred charity this year, and $10M next year.

EA-related funding is around 900 M$/year. So thinking about donations to one's top organisationg becoming 10 (= 10*10^6/(1*10^6)) times as large would make sense for expected EA-related funding in 2026 of 9 billion $ (= 10*900*10^6), 3 % (= 9*10^9/(300*10^9)) of the valuation you mention above.

Ideally, the largest funders, mainly Coefficient Giving (CG) and GiveWell, would have moved money from the years with the lowest marginal cost-effectiveness to the ones with the highest until there were no significant changes in marginal cost-effectiveness across time. I can see their predictions about the funding from Anthropic's employees not having been accurate. However, it would be a bit surprising if they were completely off to the point of marginal cost-effectiveness significantly decreasing from 2025 to 2026.