An integrated model to evaluate the impact of animal products

by kbog4 min read9th Jan 201918 comments


Impact assessmentEconomic growthDietary changeFarmed animal welfare

Edit: this is out of date, see

This Excel model combines regular and cross-price elasticity effects, welfare analysis, near- and long-term pollution to evaluate the relative harms (or benefits) of different animal products. You can look at it, or save a copy to modify it however you wish. It has some columns that you can use to evaluate a specific diet.

Link to the spreadsheet:!At2KcPiXB5rkuxZxET3jFz6Jrtr5

Sources for the more straightforward inputs are given in the spreadsheet. In this post I will describe/justify some of the more subjective inputs and elements of the model structure.

Elasticity effects regularly refer to the shift in quantity supplied when one consumer's demand increases. Other consumers buy less because of the higher price, partially offsetting one's decision. The cross-price elasticity refers to the increase in other products which are purchased as substitutes by these other consumers. If I buy 1kg of chicken, some people will buy less chicken, and some of those people will buy more of other things (e.g. turkey).

Unlike the regular effect, cross-price effects haven't been properly calculated (as far as I know). I basically guessed them for each animal product based on base rates of animal product consumption, the typical relative prices, and dietary patterns. These estimates are really not robust but they are better than nothing, feel free to replace with your own.

I found no satisfactory scale of moral weightings. Probability-of-sentience estimates given by Luke Muelhauser are inadequate because they assume that all sentient animals have equal sentience; the limited cognition and perception of simpler creatures should be considered even if we assume that they are sentient. Insufficient data is available for neuron count, and brain mass seems clearly wrong (it leads to elephants being much more important than humans, and cows much more important than pigs). Instead, I made my own estimates, based on reading basic information about the behavior and cognition of different animals, using my subjective-well-being perspective.

For quality of life I did not use Brian Tomasik's calculations, because they only quantified suffering and ignored happiness. I created a second sheet to integrate multiple groups of estimates of animal quality of life; the first is the ratings by Charity Entrepreneurship and the second is the ratings by Bailey Norwood in his book Compassion, by the Pound. I gave more weight to the former because it has multiple people's inputs, a more rigorous formal system and is done by EA researchers. However, there is a systematic difference between the two, as Norwood was more optimistic about animals' quality of life. There is also more optimism about farm animal lives coming from farmers, who are more familiar with them than anyone else. Therefore I kept the weighting for Norwood's estimates almost as high, in order to adjust for this bias that we get when we only hear one side of the story.

Neither group of estimates had estimates for every type of animal, so I created dummy estimates. First I measured the average difference in quality of life evaluations for animals which were evaluated by both sources (53, on a +100 to -100 scale), then I added or subtracted it from one source to fill in the blanks of the other. Because this is less robust than the real evaluations, I gave the dummy estimates less weight.

Both of the scales seem to have a flaw in that they are symmetric from suffering to happiness. Even under a standard utilitarian view, people and animals seem to have more capacity for suffering than for happiness; a perfect life is not enough to outweigh a terrible life. The ideal way to address this would be to redo the evaluations from the ground up, but for my purposes I used a rough workaround of adding an input parameter which lets you overweight animals with net average suffering while underweighting animals with net average happiness. This is not really precise because it is an ex post facto modification which neglects the variance in welfare within and among animal lives, but it seems to be a decent approximation (especially since the animals are mostly living in net suffering anyway, per these estimates). The default value (2) is my guesstimate from a standard utilitarian framework; more substantially 'negative-leaning' views can be modeled by providing a higher number.

The short run costs of greenhouse gases turned out to be very small and straightforward to compare with animal suffering, but the long run impact to our economy and society are a different story. If climate change hurts our economy then we may be shifted on a fundamentally slower trajectory of civilizational progress. As far as I know, there isn't a satisfactory estimate of long-run societal utility, so I attempted my own using the Doomsday Argument. Assuming a noninformative prior distribution over the eventual number of humans, the expected number of future humans is equal to the number of past humans (108.5 billion). Using the standard Self-Sampling Assumption where the observer is selected from all observers, we must input the expected lifespan of future people to calculate future utility. I chose 120 for a future with a small minority of (theoretical) immortals and/or widespread modest improvements in longevity.

If you use the Strong Self-Sampling Assumption, the observer-moment is selected from all observer-moments. You can model this with the spreadsheet - just use the average historical lifespan for the expected lifespan of future people.

We may have significant doubts about the Doomsday Argument that lead us to defer to a more basic direct estimate of expected future population and lifespans. First, the DA might be philosophically wrong, and second, humans might evolve or be replaced by agents that fall outside our reference class. In these cases, you can estimate a larger future population and/or longer future lifespans.


After viewing my results and also testing out plausible variations in the inputs, these stuck out as the main conclusions.

  • Milk is essentially unobjectionable. Even after estimating cross-price elasticity effects and environmental damage, the impact of milk is comparatively negligible. In fact the well-being of the consumer, not included in this model, may outweigh the other effects of the product. (Veal production is so low that marginal milk production should do nothing to change it; Compassion, by the Pound points out the massive fall in veal production over time.) The EA community should not push veganism except insofar as a milk exception is considered weird and difficult to communicate.
  • The beef+milk+plants diet that is often suggested as an easy way to reduce animal suffering should be dropped. Even under fairly conservative assumptions about long run climate change and social utility, the costs of beef are higher than some other animal products. A regular vegetarian diet appears to be generally better, and there is substantial uncertainty over whether beef or chicken is better. A more plausible set of inputs (the defaults in this spreadsheet) ranks beef near the bottom, and things get astronomically worse if we drop the Doomsday Argument in favor of a simpler direct estimate of future social utility.
  • Giving up fish is still extremely important under regular assumptions, arguably more important than the much harder step of moving on to a vegetarian or vegan diet. We should consider ways of targeting our activism more specifically towards fish consumption and production. This has been said before, but it remains robust under this model and needs to be stressed.
  • Short term animal suffering is the main issue under most outlooks, and dominates the issue if you have a serious expectation for some impending extinction event. Climate change concerns dominate short term welfare once you include trillions of people or millennia-long lifespans in your framework.
  • Short term morbidity and mortality from climate change seems to be much less significant than the long run slowdown in economic growth and expansion.

Link to the spreadsheet:!At2KcPiXB5rkuxZxET3jFz6Jrtr5


18 comments, sorted by Highlighting new comments since Today at 11:24 PM
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Thanks for putting this together! It's really great to see attempts at quantitatively prioritizing animal suffering, and I wish people would do more of it.

I do think you are misusing the word elasticities. The table you cite in compassion by the pound used the price elasticities of supply and demand to come up with their estimates, but these numbers they report are not elasticities, since that term usually refers to the change in demand or supply in response to price or income. 

This leaves me particularly confused as to your interpretation of what you call "cross-price elasticities"--a cross-price elasticity of demand refers to the percent increase in demand of commodity x in response to a percent increase in price of commodity y. You are using the term to refer to "the increase in other products which are purchased as substitutes by these other consumers." The reason this distinction is important is that traditional elasticities of demand account for individual consumers substituting one good for another due to price changes--they do not show the net change in equilibrium quantity of one good in response to a demand change of another good. Since you are basing this on your own assumptions rather than data, all I'm suggesting here is a rephrasing.

If you are truly looking for a cross-price elasticity of demand, these are well studied for most commodities and can be found here

My final comment is that I am puzzled by your conclusion regarding milk given that the welfare metrics you use are just scales from better to worse and do not have an interpretation for their absolute value. It could be that your metrics are exactly spot on, but milk products still impose enormous suffering on cows per pound. I'm puzzled by your conclusions regarding the relative importance of climate change for the same reason.

Anyways, thanks again for working on this. I hope my comments don't come across as too critical, as I think that carefully reasoning through these issues is really important. 

Ah, yeah, thanks for underlining that, I say "elasticity effect" as opposed to elasticity, maybe that's not clear enough.

My final comment is that I am puzzled by your conclusion regarding milk
given that t welfare metrics you use are just scales from better to
worse and do not have an interpretation for their absolute value.

The quality of life evaluations both have 0 for a life with neutral value, if that's what you mean.

Each point in the scoring corresponds to 1/100 of the difference between a neutral life and a life with all interests satisfied, for a human, for one day.

So the estimated net harm of a cup of milk is like feeling 1% worse for a day, on my assumptions.

Thanks for putting this together. If this analysis is true (though I’m skeptical), then pescatarian -> vegetarian advocacy could be beneficial. I definitely do agree that not including carbon cost in the existing calculations has long been a mistake... there are likely other considerations that are yet still missing.

Having ~1 human welfare day lost per 5kg of carbon seems high to me... and in the long run scenario close to 9 human welfare days per kg. Both of these calculations would require more defense in my opinion.

Those welfare points are on a roughly -100 to +100 point scale. It's not a real QALY.

>>There is also more optimism about farm animal lives coming from farmers, who are more familiar with them than anyone else.

I believe this familiarity is a much weaker factor than the bias farmers have to think of themselves as ethical and to justify the industry they work in.

Well we have to count countervailing biases among animal activists and utilitarians too.

Neither here nor there, but while we're counting possible biases, it may also be worth considering the possibilities that

  • people who conclude that farm animals' lives are good may select into farming, and people who conclude that they're bad may select out, making farmers "more optimistic than others" even before the self-serving bias; and, pointing the other way,
  • people who enter animal advocacy on grounds other than total utilitarianism could then have some bias against concluding that farm animals have lives above hedonic zero, since it could render their past moral efforts counterproductive (and maybe even kind of embarrassing).

I don't see Pig's 'quality of life score' in CE's original report, but I notice you used -75, which is the worst among all animals. Can someone help me find the source?

Thanks, that looks like a mistake, it should be listed as a dummy estimate. It's fixed now with a more accurate estimate, pork is slightly worse now compared to the original version.

It does seem unusually pessimistic, it is the result of combining Norwood's relative pessimism about factory farmed pork and charity Entrepreneurship's general pessimism about farm animals.

Thanks so much for putting this together! I hadn't thought of the cross-price elasticity effects across types of animal products, but of course it's an important thing to incorporate.

Two extensions of this sort of analysis that I would be interested to see:

  • Are there any important cross-price elasticity effects between animal and non-animal (including non-food) products? For instance, if the worst type of meat is beef, as you estimate, then it could be good to buy products that use the same inputs as beef--a type of grain that grows best on the types of land suitable for cattle, say--because that will push up the price of beef and push people into less harmful meat products. (It makes sense that cross-price elasticity effects would tend to be largest within kinds of meat, but other products may still worth considering, if this hasn't already been done.)
  • Just as the substitution effects across kinds of meat are presumably stronger than between meat and other things, the effects are presumably strongest within brands of a particular animal product. That is, maybe buying (less in-)humanely raised chicken or environmentally (less un-)friendly beef pushes up the price of that product in general, which causes people to consume less of it, leading to an improvement overall, even though the purchased product itself still does net damage. How much would these within-product considerations change things?

Obviously there's no end to the possible extensions, until we have a complete model of the entire economy that lets us estimate the general equilibrium impact of switching from one product to another. But maybe there are a few more elasticities that would be relatively important and tractable to consider.

I did estimate high cross-price elasticity effects between free range and cage eggs. If you add other free range/humane products to the spreadsheet then you will have to estimate CPE effects with this sort of thing in mind. The model has capacity for it, just add more rows and columns in the matrices and interpolate the formulas. You can also include different plant products if you like, but I think you are really just adding needless complexity and noise at that point, those differences seem small and nearly impossible to estimate. I lumped all plant products together with average emissions and the assumption of equal-or-nonexistent elasticity effects.

This also makes me think of whey, which is a byproduct of making cheese. Because of that, it could be a very low impact, high protein food. Ricotta cheese is made from whey (traditionally leftover from Mozzarella). Then of course there are whey protein powders and energy bars and the like - if that's your thing. I guess they used to pump it into rivers and streams, but since they cracked down on that, they started using it as filler in ice cream, adding it to baked goods, etc. Apparently in Switzerland they use it for carbonated soft-drinks and in Iceland they sell it in bottles. (All of this comes from Wikipedia).

i think carl shulman estimated chickens have 250k neurons, u could use that

It's 221 million neurons. Source:

You might be thinking about fruit flies, they have 250k

Cattle's feed climate impact could be reduced if they ate agricultural residues (like they used to and still often do in less developed countries). I don't think that grass fed beef is really better because conventional cattle are grass fed part of their lives, so having some cattle completely grass fed means that the remainder would become a smaller percent grass fed. It looks like a little bit of seaweed reduces the methane from cattle.

“The EA community should not push veganism except insofar as a milk exception is considered weird and difficult to communicate.”  

This could be a utilitarian position within effective altruism but it wouldn’t reflect a rights position.  Overall i don't think EA could take a position of not pushing veganism.  Not that it pushes veganism anyway, and never has done, instead the preference has been for the “rational pragmatism” of Shapiro, Friedrich and Ball. 

If veganism were to be promoted then it would challenge the conventional position of welfarism favoured by most leading utilitarian EAs.  Whilst we could point to some veg promotion this tends to exist in opposition to “extreme” rights views of non-exploitation and is viewed as compatible with welfarism, indeed one way to ensure that welfare standards aren’t violated is to have less domesticated animals to violate. 

I think even in terms of where we might argue that dairy is necessary for nutrition, then rights advocates would look to promote alternatives and address inequalities in terms of accessibility to plant based nutrition.  Also worth noting that Open Philanthropy funded charities RSPCA and CIWF have been promoting rose veal as a way to discourage farmers from killing calves at birth or live exporting them. 

Overall though cross-price elasticity would seem interesting for rights advocates in terms of how it might affect a shift to plant based products or alternatively toward animal products (if people are of the mind they are merely consuming products).  Though as a general matter rights advocates are addressing cultural speciesism rather than nudging consumer behaviour within systems of exploitation.     

I'd be interested to know if anyone has done an analysis like this that includes lamb or wild caught fish. The latter in particular seems like it could vary widely by species - IE killing wild fish would theoretically allow some of it's prey to live longer - though I'm sure there are many, many more factors to consider.