Scale of the welfare of various animal populations

Summary

  • I Fermi-estimated the scale of the welfare of various animal populations from the relative intensity of their experiences, moral weight, and population size.

  • Based on my results, I would be very surprised if the scale of the welfare of:

    • Wild animals ended up being smaller than that of farmed animals.

    • Farmed animals turned out to be smaller than that of humans.

An abstract oil painting of nematodes. Generated by OpenAI’s DALL-E.

Introduction

If it is worth doing, it is worth doing with made-up statistics?

Methods

I Fermi-estimated the scale of the welfare of various animal populations from the absolute value of the expected total hedonistic utility (ETHU). I computed this from the product between:

  • Intensity of the mean experience as a fraction of the median welfare range.

  • Median welfare range.

  • Population size.

The data and calculations are here.

Intensity of experience

I calculated the intensity of the mean experience of farmed animals as a fraction of their median welfare range from that of broilers in a reformed scenario[1], assuming:

  • The time they experience each level of pain defined here (search for “definitions”) is given by these data (search for “pain-tracks”) from the Welfare Footprint Project (WFP).

  • The welfare range is symmetric around the neutral point, and excruciating pain corresponds to the worst possible experience.

  • Excruciating pain is 1 k times as bad as disabling pain[2].

  • Disabling pain is 100 times as bad as hurtful pain, which together with the above implies excruciating pain being 100 k times as bad as hurtful pain.

  • Hurtful pain is 10 times as bad as annoying pain, which together with the above implies excruciating pain being 1 M times as bad as annoying pain.

  • Their lifespan is 42 days, in agreement with section “Conventional and Reformed Scenarios” of Chapter 1 of Quantifying pain in broiler chickens by Cynthia Schuck-Paim and Wladimir Alonso.

  • They sleep 8 h each day, and have a neutral experience during that time.

  • Them being awake is as good as hurtful pain is bad. This means being awake with hurtful pain is neutral, thus accounting for positive experiences.

Ideally, I would have used empirical data for the animal populations besides farmed chickens too. However, I do not think they are readily available, so I had to make some assumptions.

For the intensity of the mean experience of humans as a fraction of their median welfare range, I considered we:

  • Sleep 8 h each day, and have a neutral experience during that time.

  • Being awake is as good as hurtful pain is bad. This means being awake with hurtful pain is neutral, thus accounting for positive experiences.

For the intensity of the mean experience of wild animals as a fraction of their median welfare range, I used the same value as for humans. However, whereas I think humans have positive lives (see here), I am very uncertain about wild animals (see this preprint from Heather Browning and Walter Weit).

Median welfare range

I defined the median welfare range from Rethink Priorities’ estimates for mature individuals[3] provided here by Bob Fischer[4]. For the populations I studied with animals of different species, I used those of:

  • For wild mammals, pigs.

  • For farmed fish, salmon.

  • For wild fish, salmon.

  • For farmed insects, silkworms.

  • For wild terrestrial arthropods, silkworms.

  • For farmed crayfish, crabs and lobsters, mean between crayfish and crabs.

  • For farmed shrimps and prawns, shrimps.

  • For wild marine arthropods, silkworms.

  • For nematodes, silkworms multiplied by 0.1.

Population size

I defined the population size from:

  • For humans, these data from Our World in Data (OWID) (for 2021).

  • For wild mammals, the mean of the lower and upper bounds provided in section 3.1.5.2 of Carlier 2020.

  • For farmed chickens and pigs, these data from OWID (for 2014).

  • For farmed fish, the midpoint estimate of this analysis from Kelly Anthis and Jacy Anthis (for 2019).

  • For wild fish, the mean between the mean of the lower and upper bounds provided in section 3.1.5.5 of Carlier 2020, and the order of magnitude given in Table S1 of Barn-On 2018.

  • For farmed insects raised for food and feed, the mean of the lower and upper bounds provided here by Abraham Rowe (in the 2nd point of the section “Key Findings”).

  • For farmed crayfish, crabs and lobsters, and farmed shrimps and prawns, the ratio between the means of the lower and upper bounds for:

  • The number of individuals killed per year provided here by fishcount.org (for 2017).

  • The time in years farmed shrimps spend in grow-out ponds, developing from juvenile until market size, according to this Wikipedia page.

  • For wild terrestrial and marine arthropods, and nematodes, the orders of magnitude from Table S1 of Barn-On 2018.

Results

The results are presented in the table below by descending absolute value of ETHU as a fraction of that of humans, i.e. decreasing scale of welfare.

Population

Intensity of the mean experience as a fraction of the median welfare range

Median welfare range

Intensity of the mean experience as a fraction of that of humans

Population size

Absolute value of ETHU as a fraction of that of humans

Farmed insects raised for food and feed

12.9 μ

2.00 m

3.87 m

8.65E10

0.0423

Farmed pigs

12.9 μ

0.515

1.00

9.86E8

0.124

Humans

6.67 μ

1.00

1.00

7.91E9

1.00

Farmed crayfish, crabs and lobsters

12.9 μ

0.0305

0.0590

1.57E11

1.17

Farmed fish

12.9 μ

0.0560

0.108

1.11E11

1.52

Farmed chickens

12.9 μ

0.332

0.642

2.14E10

1.74

Farmed shrimps and prawns

12.9 μ

0.0310

0.0599

9.87E11

7.48

Farmed animals analysed here

12.9 μ

0.03620.07001.36E1212.1

Wild mammals

6.67 μ

0.515

0.515

6.75E11

43.9

Wild fish

6.67 μ

0.0560

0.0560

6.20E14

4.39 k

Wild terrestrial arthropods

6.67 μ

2.00 m

2.00 m

1.00E18

253 k

Wild marine arthropods

6.67 μ

2.00 m

2.00 m

1.00E20

25.3 M

Nematodes

6.67 μ

0.200 m

0.200 m

1.00E21

25.3 M

Wild animals analysed here

6.67 μ

0.365 m

0.365 m1.10E2150.8 M

Discussion

According to my results:

  • Wild animal welfare dominates farmed animal welfare:

    • The scale of the welfare of each of the 5 populations of wild animals exceeds that of each of the 6 populations of farmed animals.

    • The scale of the welfare of the 5 populations of wild animals is 4.21 M (= 50.8*10^6/​12.1) times that of the 6 populations of farmed animals. This did not surprise me given the sheer numbers of wild animals.

  • There is a meat-eater problem. The combined importance of the 6 populations of farmed animals I analysed is 12.1 times as large as that of humans. Consequently, a smaller human population will tend to increase welfare in the nearterm if we ignore the effects on wild animals. However, these dominate, and can be positive or negative, so I have no idea what is the overall nearterm effect of changing the size of the human population. For similar reasons, I think it is very hard to say whether GiveWell’s top charities are beneficial or harmful.

  • The intensity of the mean experience of farmed chickens, estimated from data for broilers in a reformed scenario, is 64.2 % that of humans. Intuitively, I would guess the ratio to be higher, but I believe I am biassed towards overweighting the time in disabling and excruciating pain. This is indeed super bad, but does not last for long.

  • The order of the scale of welfare among wild animals roughly matches what I estimated here based on the total number of neurons, with arthropods and nematodes being the major drivers. The welfare of nematodes has a greater scale here, but my guess for the moral weight of nematodes has quite low resilience.

  • Among the populations of farmed animals and humans, the welfare of insects raised for food and feed has the smallest scale. I actually expected it to be larger, but I think I was overestimating their population size.

The specific ordering of the various animal populations by scale of welfare I got is not robust given the high uncertainty of my results. However, I would be very surprised if the scale of the welfare of:

  • Wild animals ended up being smaller than that of farmed animals.

  • Farmed animals turned out to be smaller than that of humans.

I would say any scope-sensitive ethic will lead to these conclusions, not just expectational total hedonistic utilitarianism.

  1. ^

    From this page of WFP, broilers in reformed scenarios have an average daily gain of 45 to 46 g/​d, whereas ones in conventional scenarios have 60 and 62 g/​d.

  2. ^

    I encourage you to check this post from algekalipso, and this from Ren Springlea to get a sense of why I think the intensity can vary so much.

  3. ^

    This post from Bob Fischer looks into the moral weight of juvenile insects.

  4. ^

    Bob Fischer shared the means here, but recommended using the medians.