Comparison between the hedonic utility of human life and poultry living time

By Vasco Grilo🔸 @ 2022-06-08T07:52 (+47)

Summary

• This analysis estimates the negative utility of poultry living time as a fraction of the utility of human life, under total hedonic utilitarianism (classical utilitarisnism).
• The results are presented by country in this spreadsheet (see tab "TOC").
• The conclusions are very sensitive to the moral weight of poultry birds relative to humans, and the quality of their living conditions in factory farms relative to fully healthy life. However:
  • In expectation, the (mean) negative utility of poultry living time seems much larger than that of human life.
  • Realistically, the (median) negative utility of poultry living time seems comparable to that of human life.
• You can use this Guesstimate model to select your preferred inputs.

Acknowledgements

Thanks to Cynthia Schuck-Paim, Jason Schukraft, Lewis Bollard, Matt Sharp, Michael St. Jules and Scott Smith for feedback.

Methodology

The logic of the calculations is illustrated in this Guesstimate model. The tabs mentioned throughout the following sections refer to this spreadsheet.

All the distributions defined in the following sections were assumed to be independent.

Utility of human life

The utility of human life (QALY/person/year) was determined from the ratio between the healthy and full life expectancy. This is imperfect^[1], but allows to estimate the utility of human life via a linear regression on life expectancy at birth^[2]:

• The utility of human life was calculated through the mean life expectancy at birth of the years between 2025 and 2100 (see tab "Future utility of human life").
  • Data about the future life expectancy at birth was taken from OWID, and is in tab "Future life expectancy".
• The linear regression coefficients were calculated based on data about the healthy and full life expectancy at birth from 1990 to 2016 (see tabs "Utility of human life and life expectancy" and "Past utility of human life").
  • Data about the past healthy life expectancy at birth was taken from OWID, and is in tab "Past healthy life expectancy".
  • Data about the past life expectancy at birth was taken from OWID, and is in tab "Past life expectancy".

Utility of poultry living time

The utility of poultry living time per capita (-QALY/person/year) is the product of:

• The poultry living time per capita^[3] (pyear/person/year), which is the product between:
  • The poultry production per capita (kg/person/year).
  • The ratio between poultry living time and production (pyear/kg).
• Moral weight of poultry^[4] (QALY/pQALY).
• Quality of the living conditions of poultry^[5] (-pQALY/pyear).

The factors defining the poultry living time per capita were modelled as constants, and the ones regarding the moral weight and quality of the living conditions of poultry as distributions. The following sections provide further details. 

The calculations of the utility of poultry living time per capita by country were performed in this Google Colab program^[6], and the respective results uploaded to the tab "Utility of poultry living time per capita".

Poultry production per capita

The poultry production per capita between 2025 and 2100 (kg/person/year) was determined from the time-weighted average of those of the following periods^[7]:

• 2025 to 2050: mean between the poultry production per capita in 2025 and 2050^[8].
• 2050 to 2100: half of the poultry production per capita in 2050^[9].

The poultry production per capita in 2025 and 2050 was estimated from the ratio between the poultry production and population. The poultry production was calculated considering:

• The poultry production by country in 2018 from OWID (see tab "Poultry production").
• The poultry production annual growth rate by region, which was estimated by adding the following (see tab "Poultry production annual growth rate"):
  • Poultry population annual growth rate between 2005/2007 and 2050 from FAO 2012.
  • Poultry carcass mass annual growth rate between 2005/2007 and 2050, which was calculated based on the poultry carcass mass in 2005/2007 and 2050 from FAO 2012.
  • Product between the above^[10].
• The poultry production annual growth rate of a given country equal to that of its respectinve FAO 2012 region (see tab "Regions by country").

Population data were taken from OWID (see tab "Population").

Ratio between poultry living time and production

This metric was estimated from the ratio between the number of poultry birds^[11] (OWID; see tab "Poultry livestock counts") and poultry production by country in 2018. The calculations are in tab "Ratio between poultry living time and production".

Moral weight of poultry

The moral weight of poultry (QALY/pQALY) was modelled as the product between:

• The probability of chickens being moral patients^[12], as defined by Luke Muehlhauser here, which was set to 80 % according to this section of Open Philanthropy's 2017 Report on Consciousness and Moral Patienthood.
• A loguniform distribution whose 10th and 90th percentiles were set to 5*10^-5 and 10. These are the lower and upper bounds of the "80 % prediction interval" guessed by Luke Muehlhauser here for the moral weight of chickens relative to humans conditional on the former being moral patients^[13] (see "Moral weights of various species").

The distribution for the moral weight of poultry might depend on the theory of consciousness. The above product is implicitly assumed to represent the weighted mean of the moral weight distributions of the various theories of consciousness. These are, in turn, supposed to produce (summable) moral weight distributions in QALY/pQALY.

Quality of the living conditions of poultry

The quality of the living conditions of poultry (-pQALY/pyear) was modelled based on data from the Welfare Footprint Project (overviewed here). It was determined from the ratio between^[14]:

• The sum of the products between the time experiencing and utility of each type of pain.
• The lifespan of 42 d, in agreement with section "Conventional and Reformed Scenarios" of Chapter 1 of Quantifying pain in broiler chickens.

The time a poultry bird experiences each type of pain (h) was defined as a lognormal distribution with 5th and 95th percentiles equal to the lower and upper bound of the 90 % confidence interval (see this) estimated for a conventional scenario^[16]:

• For annoying pain: 212.82 and 436.52.
• For hurtful pain: 195.08 and 472.12.
• For disabling pain: 33.01 and 67.53.
• For excruciating pain: 8.830/3600 and 51.57/3600.

The utility of each type of pain experienced by a poultry bird (-pQALY/pyear) was defined as a lognormal distribution with 5th and 95th percentiles equal to^[17]:

• For annoying pain: 0.01 and 1.
• For hurtful pain: 0.1 and 10.
• For disabling pain: 1 and 100.
• For excruciating pain: 100 and 10 k.

The quality of the living conditions of poultry in -QALY/pyear is the product between the moral weight of poultry (QALY/pQALY) and quality of the living conditions of poultry in -pQALY/pyear.

Results

The location of the results by country in the spreadsheet is as follows^[18] (see tab "TOC"):

• Utility of human life (QALY/person/year): tab "Future utility of human life".
• Poultry living time per capita^[19] (pyear/person/year): tab "Poultry living time per capita".
• Utility of poultry living time per capita (-QALY/person/year): tab "Utility of poultry living time per capita".
• Negative utility of poultry living time as a fraction of the utility of human life: tab "Utility of human life and poultry living time".

Results are also presented below for:

• The poultry living time per capita, for 2018, 2025 to 2050, 2050 to 2100, and 2025 to 2100.
• The moral weight of poultry.
• The quality of the living conditions of poultry.
• The mean, 5th percentile, median and 95th percentile of the negative utility of poultry living time as a fraction of the utility of human life between 2025 and 2100, for the mean, 5th percentile, median and 95th percentile countries, relative to all countries and to GW countries^[20].

It is worth analysing GW countries to better understand the meat-eater problem:

The concern that some interventions aimed at helping humans might increase animal product consumption and as a result increase farmed animal suffering, e.g. by increasing real income or human population.

Poultry living time per capita

Moral weight of poultry

Quality of the living conditions of poultry

Negative utility of poultry living time as a fraction of the utility of human life

Discussion

Moral weight of poultry

This resulted in a mean moral weight of poultry of 2 QALY/pQALY^[21], which implies that 1 year of fully healthy poultry life is 2 times as valuable as 1 year of fully healthy human life. In addition, the mean equals the 82th percentile, which translates into a chance of 80% of the actual moral weight being smaller than the expected one. 

Quality of the living conditions of poultry

The mean quality of the living conditions of poultry was estimated to be 60 -pQALY/pyear and 100 -QALY/pyear. These imply 1 h of a poultry bird living in conventional conditions neutralises one of the following:

• 70 h of fully healthy poultry life.
• 200 h of fully healthy human life.

This latter value can be contextualised via a comparison with the Weighted Animal Welfare Index of Charity Entrepeneurship (CE). According to this, the negative utility per unit time of "FF [factory-farmed] broiler chicken" is:

• 1 (= (0.7*56)/(0.99*32)) times the utility per unit time of a "human in a low middle-income country".
• 0.5 (= (0.7*56)/(0.99*82)) times the utility per unit time of a "human in a high-income country".

In other words, 1 h of a poultry bird living in conventional conditions neutralises 0.5 h (= 0.483/0.927) of fully healthy human life^[22]. As a consequence, the moral weight and quality of the living conditions of poultry defined in Methodology imply the mean negative utility of poultry life is 300 (= 162/0.521) times that of the Weighted Animal Welfare Index.

One speculative explanation is that moral weight estimates tend to be underestimates because they respect the median rather than the mean. This might cause significant differences given the moral weight distribution is arguably heavy-tailed (see this note). 

• The mean quality of the living conditions of poultry in -QALY/year estimated here is 400 times as large as the median.
• The median quality of the living conditions of poultry was estimated to be 0.4 -QALY/pyear, which is 90 % (= 0.450/0.521) of the value implied by the Weighted Animal Welfare Index.

Estimating the expected (mean) moral weight is arguably better than providing median values which are as likely to be underestimates as overestimates.

Negative utility of poultry living time as a fraction of the utility of human life

The above results suggests that the negative utility of poultry living time between 2025 and 2100 is:

• For the mean country:
  • In expectation, much larger than that of human life: the mean fraction is 800.
  • Optimistically, much smaller than that of human life: the 5th percentile fraction is 0.1 %.
  • Realistically, comparable to that of human life: the mean fraction is 2.
  • Pessimistically, much larger than that of human life: the 95th percentile fraction is 2 k.
• For the mean GW country:
  • In expectation, much larger than that of human life: the mean fraction is 500.
  • Optimistically, much smaller than that of human life: the 5th percentile fraction is 0.1 %.
  • Realistically, comparable to that of human life: the mean fraction is 1.
  • Pessimistically, much larger than that of human life: the 95th percentile fraction is 2 k.

Consequently, assuming that saving one life could be approximated as a unitary increase of the population size, which is unclear, the reduction of the cost-effectiveness of GiveWell's top life-saving charities caused by accounting for poultry welfare might be significant.

Further work

For better understanding the meat-eater problem, it would be important to:

• Narrow the uncertainty regarding the moral weight and quality of the living conditions of poultry.
• Define the quality of the living conditions of poultry as a function of the country, and model their future evolution.
• Consider the indirect effects of consuming animals (e.g. How Rainforest Beef Production Affects Wild-Animal Suffering).
• Include the direct effects of consuming other factory-farmed animals besides poultry (namely fish^[23]).
• Take into account the elasticity of supply and demand^[24].

1. ^{^}

   1 QALY (quality-adjusted life year) equates to 1 year of a human in perfect health. For this analysis, I considered health as defined by the WHO: "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". However, as noted here, "there is considerable disagreement over what the QALY represents, and what it ought to represent". The meaning of 1 QALY is ultimately related to how it was assessed (e.g. whether non-physical health is included).

2. ^{^}

   The coefficient of determination (R^2) for the mean and median country were 52 % and 57 %. Other regressions were tested, but these did not result in significantly better correlations (see tab "Utility of human life and life expectancy"):

   • The linear regression of the utility of human life on the logarithm of life expectancy at birth resulted in mean and median coefficients of determination of 53 % and 58 %.
   • The linear regression of the logartithm of the utility of human life on life expectancy at birth resulted in mean and median coefficients of determination of 52 % and 57 %.
   • The linear regression of the logartithm of the utility of human life on the logarithm of life expectancy at birth resulted in mean and median coefficients of determination of 52 % and 58 %.
3. ^{^}

   1 pyear/person/year means 1 year of poultry living time per person per year.

4. ^{^}

   1 poultry QALY (pQALY) refers to 1 year of a poultry bird in perfect health. As suggested here, this could be interpreted "as [a chicken] living with all needs met, no or minimal fear of predation and disease-free (e.g. perhaps the best moments on a very good farm animal sanctuary)".

5. ^{^}

   1 -pQALY/pyear means 1 negative poultry QALY per year of poultry living time. The moral value of a poultry bird experiencing 1 negative pQALY (-pQALY) plus 1 year in perfect health is neutral.

6. ^{^}

   The Monte Carlo simulations of Guesstimate rely on 5 k samples, which was not sufficient to stabilise the results. The Google Colab program facilitates the calculation of results by country, and was run with 10 M samples in about 1 min.

7. ^{^}

   1/3 (= 25/75) of the value for 2025 to 2050, plus 2/3 (= 50/75) of that for 2050 to 2100.

8. ^{^}

   Analogous to assuming it varies linearly between 2025 and 2050.

9. ^{^}

   Analogous to assuming it decreases linearly between 2050 and 2100, and reaches 0 in 2100, which seems optimistic. The reduction could be caused by moral circle expansion or technological innovation of plant-based products.

10. ^{^}

    The growth rate of a b as a function of the growth rates of a and b, GRA and GRB, is (1 + GRA) (1 + GRB) - 1 = GRA + GRB + GRA GRB.

11. ^{^}

    "Measured as the number of live animals at a single point".

12. ^{^}

    Poultry birds could be chickens or turkeys, which could have different moral weights and living conditions. However, the difference does not appear to be significant. Based on the Weighted Animal Welfare Index of Charity Entrepeneurship, the welfare score (whose scale ranges from -100 to 100) of factory-farmed broiler chickens is -56, and that of factory-farmed turkeys is -57.

13. ^{^}

    Choosing a lognormal distribution would lead to a moral weight of 2 kQALY/pQALY, which appears unreasonably high. As noted here, "it appears unlikely that evolution would select for animals with a non-contiguous range that was exclusively extraordinarily strong because extremely intense experiences are distracting in a way that appears likely to reduce fitness". 

    In addition, selecting a heavy-tailed distribution (e.g. loguniform instead of uniform) also seems more reasonable:

    • Negative moral weights are avoided.
    • Intuitively, moral weight seems to be a product (not a sum) of the dimensions of moral weight described here (clock speed of consciousness, unity of consciousness, and unity-independent intensity of valenced aspects of consciousness).
14. ^{^}

    Neutral utility is implicitly assumed when poultry birds are not in pain, what agrees with the WFP modelling for sleeping. According to Box 3 of section "Conventional and Reformed Scenarios" of Chapter 1 of Quantifying pain in broiler chickens:

    • "We [Welfare Footprint Project] conservatively assume that pain is not felt when individuals are sleeping".
    • "The duration ranges assumed in the Pain-Tracks presented in this book therefore consider a wide range of hypotheses for the time broiler chickens spend fully awake per day, with minimum and maximum sleeping times of 4 and 10 hours, respectively".
    • "Since young chicks may sleep for longer periods, we assume minimum and maximum sleeping times of 8 and 14 hours, respectively, in the first two weeks of life".
15. ^{^}

    According to Cynthia Schuck-Paim, "data on typical times of onset of the many welfare challenges affecting broilers is not available in the literature, but our guess would be something between 5% to 20% of the approximately 42 days of existence".

16. ^{^}

    The values are given in the interactive chart "Total Time in Pain" of this page. The 4 types of pain are described in Box 1 of Chapter 1 of Quantifying pain in broiler chickens. Note that it is possible to experience multiple types of pain simultaneously.

    The "conventional scenario" is represented by the use of "fast-growing breeds" (in contrast to "a slower-growing strain" of the "reformed scenario"; see section "Conventional and Reformed Scenarios").

17. ^{^}

    The percentiles were defined based on my intuition and the description of the types of pain. The geometric mean of the defined percentiles implies null median utility for 1 h of fully healthy poultry life plus one of the below experiences:

    • 10 h of annoying pain.
    • 1 h of hurtful pain.
    • 6 min of disabling pain.
    • 4 s of excruciating pain.
18. ^{^}

    The GW countries are listed in tab "Countries of GiveWell's top life-saving charities", and their results were highlighted in blue in the spreadsheet.

19. ^{^}

    A poultry living time per capita of 1 pyear/person/year means that 1 year of poultry living time is caused per person per year.

20. ^{^}

    Here, "GW countries" are the ones in 2022 GiveWell cost-effectiveness analysis — version 4 which concern GiveWell's top life-saving charities. These are AMF, Malaria Consortium, Helen Keller International, and New Incentives.

21. ^{^}

    Note that this result refers to the mean moral weight of poultry birds relative to humans, which is not equal to the reciprocal of the mean moral weight of humans relative to poultry birds. This could be understood by noting that the mean of X is not equal to the reciprocal of the mean of 1/X (i.e. E(X) is not equal to 1/E(1/X)). 

22. ^{^}

    Assuming the utility of human life in high-income countries is 0.927 QALY/year, as estimated for the median and 95th percentiles countries.

23. ^{^}

    The total negative utility of the living time regarding factory-farmed fish and poultry might be similar:

    • Their populations contain a similar number of neurons (but note that this might not be relevant):
      • 10 E neurons for factory-farmed fish: 1 T fish in traditional aquaculture times 10 M neurons of an adult zebrafish.
      • 5 E neurons for factory-farmed broiler chickens: 21.41 G chickens times 221 M neurons of the red junglefowl.
    • The utility of their living time might be similar:
      • Based on the Weighted Animal Welfare Index of Charity Entrepeneurship, the welfare score (whose scale ranges from -100 to 100) of factory-farmed fish in traditional aquaculture is -44, and that of factory-farmed broiler chickens is -56.
24. ^{^}

    These determine the extent to which an increase in consumption (e.g. due to saving lives) ultimately leads to increased production.