The views expressed here are my own, not those of my employers or people who provided feedback.

Summary

• I investigate whether saving human lives globally, and in China, India and Nigeria may be harmful accounting for the meat-eater problem, i.e. the nearterm increase in farmed animal suffering caused by increasing income or population.
• I estimate a random person globally, and in China, India and Nigeria in 2022 caused 15.5, 34.6, 5.17 and 2.31 times as much suffering to poultry birds and farmed aquatic animals as the person’s happiness. Moreover, I expect the meat-eater problem in those countries to become worse in the nearterm as their real gross domestic product (real GDP) per capita increases. So my results suggest extending human lives there is harmful in the nearterm.
• GiveWell has made 1.09 billion dollars of grants impacting people in the countries I mentioned. Ambitious Impact has incubated 8 organisations whose 1st target country was one I mentioned, and whose interventions significantly increase the nearterm consumption of farmed animals.
• Nevertheless, I am not confident that saving human lives globally, and in China, India or Nigeria is harmful to animals:
  • Even if it is so for farmed animals nearterm, it can still be beneficial overall. For example, I would say at least chickens’ lives can become positive over the next few decades in some animal-friendly countries.
  • Many of my modelled inputs are highly uncertain. However, this means extending human lives globally, and in China, India and Nigeria may be, in the nearterm, not only beneficial, but also hugely harmful.
• At the very least, I think GiveWell and Ambitious Impact should practice reasoning transparency, and explain in some detail why they neglect effects on farmed animals.
• In addition, I encourage people there to take uncertainty seriously, and, before significant further investigation, only support interventions which are beneficial in the nearterm accounting for effects on farmed animals. This favours interventions which mostly decrease morbidity instead of mortality, improving annual human welfare per capita without significantly affecting life expectancy, like ones in mental health.
• GiveWell and Ambitious Impact could also offset the nearterm harm caused to farmed animals by funding the best animal welfare interventions.
• I extend my recommendations to GiveWell and Ambitious Impact to all organisations and people supporting interventions significantly increasing the nearterm consumption of farmed animals.

Introduction

I investigate whether saving human lives in China, India and Nigeria may be harmful accounting for the meat-eater problem, i.e. the nearterm increase in farmed animal suffering caused by increasing income or population. Relatedly, you may like Kyle Fish’s post Net global welfare may be negative and declining.

Methods

I obtain the harms caused to poultry birds, and farmed aquatic animals as a fraction of the direct benefits of human life in 2022 from the ratio between:

• The sum between the harms caused to poultry birds, farmed aquatic animals excluding shrimp, and shrimp per person in 2022 in disability-adjusted life years (DALYs).
• The direct benefits of human life per person in 2022 in terms of averted DALYs.

I calculate the harms caused to each of the 3 groups of animals per person in 2022 in DALYs multiplying:

• The animals per person in 2022. I use:
  • Data on the population, number of poultry birds, and aquaculture production from Our World in Data (OWID).
  • Data on the shrimp supply per capita by country, and farmed and wild shrimp supply globally from Rethink Priorities (RP). I rely on these global estimates to calculate the farmed shrimp supply per capita by country, although one would ideally use data by country.
  • My estimate of the mass per farmed fish globally in 2019 of 1.08 kg, which I assume to be the mass per farmed aquatic animal excluding shrimp. One would ideally use data by country, and account for different species.
  • My estimate of the mass per farmed shrimp globally in 2020 of 0.0322 kg. One would ideally use data by country.
• The welfare burden per animal per year. I compute this multiplying:
  • The welfare per animal per year in animal quality-adjusted life year (AQALYs). For:
    • Poultry birds, and farmed aquatic animals excluding shrimp, I use my estimate of -2.27 AQALYs for broilers in a conventional scenario, which implies 2.27 animal-years of practically maximally happy life would be needed to neutralise 1 animal-year in the assumed conditions.
    • Farmed shrimp, I use -7.13 AQALYs, which is a mean between my estimates of -8.77, -4.40 and -4.19 AQALYs for decapod shrimp on an ongrowing farm with air asphyxiation, ice slurry and electrical stunning slaughter, weighted by 95 %, 5 % and 0 %. These weights are informed by my estimates that 95 % and 5 % of the shrimp helped by Shrimp Welfare Project’s Humane Slaughter Initiative, which has focussed on India, were originally slaughtered via air asphyxiation and ice slurry.
  • The benefits of 1 AQALY in the animals in terms of averted DALYs, which I set to:
    • For poultry birds, RP’s median welfare range of chickens of 0.332.
    • For farmed aquatic animals excluding shrimp, the mean between RP’s median welfare ranges of carp and salmon of 0.089 and 0.056, which is 0.0725.
    • For farmed shrimp, RP’s median welfare range of shrimp of 0.031.

I estimate the direct benefits of human life per person in 2022 in terms of averted DALYs from 1 minus the years lived with disability per person in 2022.

Here are the calculations.

Results

Discussion

Meat-eater problem

I estimate a random person globally, and in China, India and Nigeria in 2022 caused 15.5, 34.6, 5.17 and 2.31 times as much suffering to poultry birds and farmed aquatic animals as the person’s happiness. Moreover, I expect the meat-eater problem in those countries to become worse in the nearterm as their real GDP per capita increases. So my results suggest extending human lives there is harmful in the nearterm.

GiveWell has made 1.09 billion dollars of grants impacting people in the countries I mentioned, overwhelmingly via decreasing mortality and morbidity^[1], according to their grants database on 7 December 2024. Ambitious Impact has incubated 8 organisations whose 1st target country was one I mentioned, and whose interventions significantly increase the nearterm consumption of farmed animals, which I considered to be any significantly decreasing human mortality. Such organisations are Charity Science Health (incubated in 2016; firstly targeted India; merged with Suvita), Suvita (2019; India), Ansh (2023; India), Clear Solutions (2023; Nigeria), HealthLearn (2023; Nigeria), Notify Health (2024; Nigeria), Oxygen Access Project (2024; Nigeria), and Taimaka (2024; Nigeria).

The harms would be smaller for a random person helped by such GiveWell’s grants or Ambitious Impact’s organisations. I assume they have an income below that of a random person in the respective country, the supply per capita of meat excluding aquatic animals roughly increases with the logarithm of the real GDP per capita, and I guess so do the number of poultry birds, farmed aquatic animals excluding shrimp, and shrimp per capita. Yet, self-reported life satisfaction also roughly increases with the logarithm of the real GDP per capita. So I believe the harms to farmed animals per person increase roughly linearly with self-reported life satisfaction, at least across countries. As a result, it is unclear to me whether the harms to farmed animals as a fraction of the human benefits would be higher or lower for a random person than for a random person helped by such GiveWell’s grants or Ambitious Impact’s organisations.

Nevertheless, I am not confident that saving human lives in China, India or Nigeria is harmful to animals. Even if it is so for farmed animals nearterm, it can still be beneficial overall:

• I would say at least chickens’ lives can become positive over the next few decades in some animal-friendly countries. Relatedly, I would ideally determine the welfare burden per animal per year by country, although it is unclear to me whether I am over or underestimating it. Furthermore, I guess better worsening conditions now imply a longer time until reaching positive lives, and therefore a longer time until increased consumption of farmed animals being beneficial.
• I can see saving human lives being beneficial due to decreasing the number of wild animals with negative lives, although no one really knows whether this is the case or not.
• It is unclear to me whether saving lives increases or decreases person-years. It increases these nearterm via increasing population, but may decrease them longterm, as lower child mortality is associated with lower fertility, which can lead to a smaller longterm population. Note human welfare may be decreased in this case.
• I assume improved human conditions increase the success of animal welfare interventions, for example, via greater willingness to pay for higher welfare products. In any case, I expect more targeted approaches explicitly optimising for animal welfare to be much more cost-effective.

Besides not touching on all of these considerations, many of my modelled inputs are highly uncertain too. However, this means extending human lives globally, and in China, India and Nigeria may be, in the nearterm, not only beneficial, but also hugely harmful. Using RP’s 5th and 95th percentile welfare range of shrimp of 0 and 1.15, and maintaining all the other inputs, the harms caused to poultry birds and farmed aquatic animals as a fraction of the direct benefits of human life in 2022 would be:

• Globally, 5.61 to 372.
• In China, 12.3 and 841.
• In India, 1.70 and 131.
• In Nigeria, 1.12 and 45.3.

Suggestions

At the very least, I think GiveWell and Ambitious Impact should practice reasoning transparency, and explain in some detail why they neglect effects on farmed animals. By ignoring uncertain effects on farmed animals, GiveWell and Ambitious Impact are implicitly assuming they are certainly irrelevant. I find this view quite extreme, given the large uncertainty involved, and I am not aware of GiveWell or Ambitious Impact having justified it in anything close to sufficient detail.

In addition, I encourage people there to take uncertainty seriously, and, before significant further investigation, only support interventions which are beneficial in the nearterm accounting for effects on farmed animals. This favours interventions which mostly decrease morbidity instead of mortality, improving annual human welfare per capita without significantly affecting life expectancy, like ones in mental health.

GiveWell and Ambitious Impact could also offset the nearterm harm caused to farmed animals by funding the best animal welfare interventions. I calculate these are over 100 times as cost-effective as GiveWell’s top charities ignoring their effects on animals. If so, and some funding from GiveWell or Ambitious Impact is neutral due to negative effects on animals, these could be neutralised by donating less than 1 % (= 1/100) of that funding to the best animal welfare interventions.

I believe Ambitious Impact is clearly beneficial, as 20.9 % of the organisations they incubated targeted helping animals, including the super cost-effective Shrimp Welfare Project. Nonetheless, it is hard for me to see how that justifies starting organisations apparently causing lots of nearterm harm with unclear longterm effects.

I extend my recommendations to GiveWell and Ambitious Impact to all organisations and people supporting interventions significantly increasing the nearterm consumption of farmed animals. I have focussed on:

• GiveWell because:
  • They are the lead evaluator of global health and development (GHD) interventions.
  • They have granted lots of money to interventions significantly decreasing human mortality in countries where the meat-eater problem is a major concern.
  • They have plenty of resources to practice reasoning transparency as well as investigate the effects on farmed animals, estimating “they collectively conduct more than 50,000 hours of research per year”.
  • The cost-effectiveness analyses of their top charities have hundreds of rows, and include adjustments which change their cost-effectiveness by as little as 1 %, but completely neglect effects on farmed animals that can easily have a way larger impact.
• Ambitious Impact because:
  • They are the lead incubator of GHD organisations.
  • They have incubated many GHD organisations working in countries where the meat-eater problem is a major concern.
  • They are less willing to incubate organisations whose cost-effectiveness considering only humans is very uncertain, so I believe they should do as much when the cost-effectiveness accounting for humans and animals is very uncertain.
  • Joey Savoie, their CEO, said they “consider cross-cause effects in all the interventions we consider/recommend, including possible animal effects and WAS [wild animal suffering] effects”.
  • I think they intrinsically value not only expected impact, but also about avoiding harm. This agrees with Joey’s quote above, but not with risking causing lots of harm to animals.

Carbon and farmed animal welfare footprint

I estimate greenhouse gas (GHG) emissions have harms to humans of 0.00957 DALY/tCO2eq. The global GHG emissions per capita in 2022 were 6.6 tCO2eq, so I calculate the annual GHG emissions of a random person in 2022 caused harms to humans of 0.0632 DALY (= 0.00957*6.6), i.e. 7.16 % (= 0.0632/0.883) of my estimate for the direct benefits of human life per person in 2022. This is much lower than 1, so I believe extending human lives increases human welfare despite the negative effects of GHG emissions, even without considering indirect effects like humans working on decreasing emissions. As a result, I do not see a clear argument for degrowth on the basis of decreasing the harms to humans from GHG emissions.

I can much more easily see an argument for not extending human lives due to negative effects on farmed animals. My estimate for the harms caused to poultry birds and farmed aquatic animals per person in 2022 of 13.7 DALY is:

• 217 (= 13.7/0.0632) times my estimate for the harms to humans of the annual GHG emissions of a random person in 2022. Relatedly, I think replacing chicken meat with beef or pork is better than the reverse.
• 15.5 times my estimate for the direct benefits of human life per person in 2022, which is much higher than 1.

The good news is that the best animal welfare interventions are super cost-effective. I calculate neutralising the harms caused to poultry birds and farmed aquatic animals per person in 2022 only requires donating:

• 8.20 $ (= 13.7/1.67) to broiler welfare corporate campaigns.
• 2.98 $ (= 13.7/4.59) to cage-free corporate campaigns.
• 0.0214 $ (= 13.7/639) to the Shrimp Welfare Project (SWP).

Despite the above, I follow a plant-based diet, and agree with Marcus Abramovitch’s reasons for doing so.

Acknowledgements

Thanks to Filip Murár, Joey Savoie, Samuel Hilton and Vicky Cox for feedback on the draft^[2].

1. ^{^}

    I think the vast majority of GiveWell’s grants to boost income respect deworming, and this accounted for only 61.8 M$ in the context of the 3 countries, i.e. 5.67 % (= 61.8*10^6/(1.09*10^9)) of the total money granted to those.

2. ^{^}

    I listed the names alphabetically.