I will respond with my interpretation of the report, so that the author might correct me to help me understand it better.
If you ask “If we have an option between preventing the birth of Sabs versus preventing the birth of an average chicken, how many chickens is Sabs worth?” then Sabs might be worth −10 chickens since chickens have net negative lives whereas you (hopefully) have a net positive life.
If you ask “Let’s compare a maximally happy Sabs and maximally happy chickens, how many chickens is Sabs worth?”, I don’t think these estimates respond to that either. It might be the case that chickens have a very large welfare range, but this is mostly because they have a potential for feeling excruciating pain even though their best lives are not that good.
I think you need to complement this research with “how much the badness of average experiences of animals compare with each other” to answer your question. This report by Rethink Priorities seems to be based on the range between the worst and the best experiences for each species.
This is exactly right, Emre. We are not commenting on the average amount of value or disvalue that any particular kind of individual adds to the world. Instead, we’re trying to estimate how much value different kinds of individuals could add to the world. You then need to go do the hard work of assessing individuals’ actual welfare levels to make tradeoffs. But that’s as it should be. There’s already been a lot of work on welfare assessment; there’s been much less work on how to interpret the significance of those welfare assessments in cross-species decision-making. We’re trying to advance the latter conversation.
Bob, do you have any recommendations for where I could find estimates of the welfare of common farmed animals, ideally including chickens, pigs, cows, and shrimp? I found some “Life Quality” scores in the Supplementary Materials of Scherer (2018), but it often scores farmed cows as having a much lower life quality than farmed pigs, which seems implausible to me.
That’s a tough one, Chris. I assume you’re looking for something like, “On a −1 to 1 scale, the average welfare of broiler chickens is −0.7, the average welfare of pigs is −0.1, the average welfare of cattle is 0.2, etc.” Is that right? The closest thing to that would be the scores that Norwood and Lusk give in Compassion by the Pound, though not for shrimp, and I also tend to think that their numbers skew high. For the most part, animal welfare scientists aren’t interested in scoring welfare on a cardinal scale, so it’s an oddity when they try. (Marc Bracke is one exception, though I don’t think you’re going to get what you want from his papers either.) I’m sorry that I can’t be of more help!
> For the most part, animal welfare scientists aren’t interested in scoring welfare on a cardinal scale, so it’s an oddity when they try.
Just to confirm, you and Rethink Priorities are using a cardinal scale for your welfare ranges, right? So when you say that a cow has a welfare range of 0.5, you implicitly mean that there is some universal scale where a cow’s minimal welfare is −0.25 and maximum is +0.25 (or shifted if we don’t assume symmetry).
I guess I’m confused on why there isn’t more work on estimating the average realized values of welfare, both from Rethink and from other animal welfare scientists. Those values are necessary for foundational claims like “eating 1000 calories of beef creates demand for X units of suffering”, or “moving cows to a pasture will increase welfare by Y units”.
Yes, Chris: we’re using a cardinal scale. To your point about estimating the average realized values of welfare, I agree that this would be highly valuable. Animal welfare scientists don’t do it because they don’t face decisions that require it. If you’re primarily responsible for studying broiler welfare, you don’t need to know how to compare broiler welfare with pig welfare. You just need to know what to recommend to improve broiler welfare. As for RP, we’d love to work on this and I’ve proposed such projects many times. However, this work has never been of sufficient interest to funders. If that changes, you can bet I’ll devote a lot of time to it!
I estimate broilers in conventional and reformed scenarios have a welfare of −2.27 and −0.161 AQALY/broiler-year, and hens in conventional cages and cage-free aviaries have a welfare of −1.69 and −0.333 AQALY/hen-year[1]. I estimate shrimps on ongrowing farms not stunned, stunned with ice slurry (although note this is rarely done properly), and eletrically stunned before slaughter have a welfare of −8.77, −4.40 and −4.19 AQALY/shrimp-year. For comparing effects across species, I get estimates for the welfare in QALY/animal-year multiplying the welfare in AQALY/animal-year by Rethink Priorities’ (RP’s) median welfare ranges based on my guess that the welfare per animal-year of fully happy life is proportional to the welfare range.
To calculate the welfare in AQALY/animal-year, I assumed the welfare of annoying, hurtful, disabling, and excruciating pain are −0.1, −1, −10, and −100 k AQALY/pain-year, which imply each of the following neutralise 1 day of fully happy life:
10 days (= 1⁄0.1) of annoying pain.
1 day of hurtful pain.
2.40 h (= 24⁄10) of disabling pain.
0.864 s (= 24*60^2/(100*10^3)) of excruciating pain.
There is lots of uncertainty. Feel free to make copies of the sheets I linked above, and update the pain intensities in the tab “Pain intensities”.
To illustrate, 2.27 fully happy broiler-years, as in healthy broilers in a sanctuary, are needed to neutralise 1 broiler-year in a conventional scenario, which has a welfare of −2.27 animal quality-adjusted life-years (AQALYs) per broiler-year.
Thank you for the prompt reply Bob. Just to be clear, I am happy about the scope of this project and am impressed by its quality. I do not intend to criticise the report for being mindful about its scope.
I will respond with my interpretation of the report, so that the author might correct me to help me understand it better.
If you ask “If we have an option between preventing the birth of Sabs versus preventing the birth of an average chicken, how many chickens is Sabs worth?” then Sabs might be worth −10 chickens since chickens have net negative lives whereas you (hopefully) have a net positive life.
If you ask “Let’s compare a maximally happy Sabs and maximally happy chickens, how many chickens is Sabs worth?”, I don’t think these estimates respond to that either. It might be the case that chickens have a very large welfare range, but this is mostly because they have a potential for feeling excruciating pain even though their best lives are not that good.
I think you need to complement this research with “how much the badness of average experiences of animals compare with each other” to answer your question. This report by Rethink Priorities seems to be based on the range between the worst and the best experiences for each species.
This is exactly right, Emre. We are not commenting on the average amount of value or disvalue that any particular kind of individual adds to the world. Instead, we’re trying to estimate how much value different kinds of individuals could add to the world. You then need to go do the hard work of assessing individuals’ actual welfare levels to make tradeoffs. But that’s as it should be. There’s already been a lot of work on welfare assessment; there’s been much less work on how to interpret the significance of those welfare assessments in cross-species decision-making. We’re trying to advance the latter conversation.
Bob, do you have any recommendations for where I could find estimates of the welfare of common farmed animals, ideally including chickens, pigs, cows, and shrimp? I found some “Life Quality” scores in the Supplementary Materials of Scherer (2018), but it often scores farmed cows as having a much lower life quality than farmed pigs, which seems implausible to me.
https://link.springer.com/article/10.1007/s11367-017-1420-x
That’s a tough one, Chris. I assume you’re looking for something like, “On a −1 to 1 scale, the average welfare of broiler chickens is −0.7, the average welfare of pigs is −0.1, the average welfare of cattle is 0.2, etc.” Is that right? The closest thing to that would be the scores that Norwood and Lusk give in Compassion by the Pound, though not for shrimp, and I also tend to think that their numbers skew high. For the most part, animal welfare scientists aren’t interested in scoring welfare on a cardinal scale, so it’s an oddity when they try. (Marc Bracke is one exception, though I don’t think you’re going to get what you want from his papers either.) I’m sorry that I can’t be of more help!
Thanks Bob, much appreciated.
> For the most part, animal welfare scientists aren’t interested in scoring welfare on a cardinal scale, so it’s an oddity when they try.
Just to confirm, you and Rethink Priorities are using a cardinal scale for your welfare ranges, right? So when you say that a cow has a welfare range of 0.5, you implicitly mean that there is some universal scale where a cow’s minimal welfare is −0.25 and maximum is +0.25 (or shifted if we don’t assume symmetry).
I guess I’m confused on why there isn’t more work on estimating the average realized values of welfare, both from Rethink and from other animal welfare scientists. Those values are necessary for foundational claims like “eating 1000 calories of beef creates demand for X units of suffering”, or “moving cows to a pasture will increase welfare by Y units”.
Yes, Chris: we’re using a cardinal scale. To your point about estimating the average realized values of welfare, I agree that this would be highly valuable. Animal welfare scientists don’t do it because they don’t face decisions that require it. If you’re primarily responsible for studying broiler welfare, you don’t need to know how to compare broiler welfare with pig welfare. You just need to know what to recommend to improve broiler welfare. As for RP, we’d love to work on this and I’ve proposed such projects many times. However, this work has never been of sufficient interest to funders. If that changes, you can bet I’ll devote a lot of time to it!
Hi Chris,
I estimate broilers in conventional and reformed scenarios have a welfare of −2.27 and −0.161 AQALY/broiler-year, and hens in conventional cages and cage-free aviaries have a welfare of −1.69 and −0.333 AQALY/hen-year[1]. I estimate shrimps on ongrowing farms not stunned, stunned with ice slurry (although note this is rarely done properly), and eletrically stunned before slaughter have a welfare of −8.77, −4.40 and −4.19 AQALY/shrimp-year. For comparing effects across species, I get estimates for the welfare in QALY/animal-year multiplying the welfare in AQALY/animal-year by Rethink Priorities’ (RP’s) median welfare ranges based on my guess that the welfare per animal-year of fully happy life is proportional to the welfare range.
To calculate the welfare in AQALY/animal-year, I assumed the welfare of annoying, hurtful, disabling, and excruciating pain are −0.1, −1, −10, and −100 k AQALY/pain-year, which imply each of the following neutralise 1 day of fully happy life:
10 days (= 1⁄0.1) of annoying pain.
1 day of hurtful pain.
2.40 h (= 24⁄10) of disabling pain.
0.864 s (= 24*60^2/(100*10^3)) of excruciating pain.
There is lots of uncertainty. Feel free to make copies of the sheets I linked above, and update the pain intensities in the tab “Pain intensities”.
To illustrate, 2.27 fully happy broiler-years, as in healthy broilers in a sanctuary, are needed to neutralise 1 broiler-year in a conventional scenario, which has a welfare of −2.27 animal quality-adjusted life-years (AQALYs) per broiler-year.
Thank you for the prompt reply Bob. Just to be clear, I am happy about the scope of this project and am impressed by its quality. I do not intend to criticise the report for being mindful about its scope.
Didn’t take it that way at all! I appreciate your taking the time to comment and help clarify what we’ve done.