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Strong longtermism states that when making a decision, we should primarily consider its long-term effects.

From this perspective, the argument that one should not eat meat because it causes more animals to be farmed is weaker since the (relatively) short-term effect of an additional animal being farmed is dwarfed by the long-term effects of eating animals.

Are there any fleshed-out, longtermist arguments out there on why people shouldn't eat meat?

Also, I would be interested to know how the damage done by eating meat compares to the positive impact of donating money. Having such a comparison would allow us to price the damage done by eating meat.




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I worry that longtermism can be used to justify, or rationalize (depending on your view), too much. Imagine turning back the clock to when many of the things we consider morally wrong and abhorrent were more commonplace and were widely accepted: sexual harassment, marital rape, human slavery, etc., and sticking one's neck out in opposition to any of them would at least cost some social capital if not more.

Does the longtermist in any of these contexts really not have any obligation to engage in any costly opposition to the wrongs because it would detract from their longtermist projects? It seems it would require an awful lot of confidence in the longtermist's ability to affect the future to argue so. And it feels terribly convenient for the longtermist to argue they are in the moral right while making no effort to counteract or at least not participate in what they recognize as moral wrongs.

My view can be boiled down to this: First, we should be wary of arguments that tell us that doing things that we believe to be wrong are fine to do. Second, we should think hard about how much certainty we have about our ability to have longterm effects.

And it feels terribly convenient for the longtermist to argue they are in the moral right while making no effort to counteract or at least not participate in what they recognize as moral wrongs.

This is only convenient for the longtermist if they do not have equivalently demanding obligations to the longterm. Otherwise we could turn it around and say that it's "terribly convenient" for a shorttermist to ignore the longterm future too.

To summarize:

Eating meat -> narrower moral circle not sufficiently valuing the welfare of artificial sentience and/or wild animals -> existential risks (mostly suffering risks)

Animals and longtermism (although not specifically about your own diet):

Comparing diet to charity (often older charity cost-effectiveness estimates):

Animal charities and interventions, with newer estimates:

See also the comments.

I think there are also psychological effects of eating meat that might cause people to not give animals the moral weight they would think they deserve upon careful reflection.

See also my 2018 EAG talk on shaping the long-term future through antispeciest legislative initiatives. Most of the relevant discussion starts at 8:40.


While I at the time thought the dominant beneficial effect would be through AGI alignment, I now think that we should think of these interventions as improving the value alignment of humanity and our descendents in general.

And cf. my and Jeff Sebo's paper on the indirect effects of eating meat and farming animals on human moral psychology and its importance for consequentialists:


... (read more)

Self-plugging as I've written about animal suffering and longtermism in this essay:


To summarise some key points, a lot of why I think promoting veganism in the short term will be worthwhile in the long term is values spreading. Given the possibility of digital sentience, promoting the social norm of caring about non-human sentience today could have major long term implications.

People are already talking about introducing plants, insects and animals to Mars as a means of terraforming it. This would enormously increase the amount of wild-animal suffering. Even if we never leave our solar system, terraforming just one body, let alone several, could near double the amount of wild-animal suffering. There's also the possibility of bringing factory farms to Mars. I'm studying a PhD in space science and still get shut down when I try to say 'hey lets maybe think about not bringing insects to Mars'. This is far off from being a practical concern (maybe 100-1000 years) but it's never too early to start shifting social norms.

I'd call this mid term rather than long term, but the impacts of animal agriculture on climate change, zoonotic disease spread and antibiotic resistance are significant.

I'd like to echo Peter's point as well. We don't ask these questions for a lot of other actions that would be unethical in the short term. There seems to be a bias in EA circles of asking this kind of question about non-human animal exploitation. I'm more arguing for consistency than saying we can't argue that a short term good has a long term bad resulting in net bad.

I'd call this mid term rather than long term, but the impacts of animal agriculture on climate change, zoonotic disease spread and antibiotic resistance are significant.

Aren't those extinction risks, although perhaps less severe or likely to cause extinction than others, according to EAs?

I guess that would indeed make them long term problems, but my reading on them seems to have been that they are catastrophic risks rather than existential risks, as in they don't seem to have much likelihood (relative to other X-risks) of eliminating all of humanity.

I agree with the previous answers- that is, I think the best argument here has to do with moral circle expansion affecting the long term future.

In addition, eating meat could increase existential risk through its effects on worsening climate change and the emergence of natural pandemics.

See this chart to compare greenhouse gas emissions per kg of different food products to see how much more animal products contribute to climate change. In total, animal agriculture contributes around 14% to 18% of all anthropogenic greenhouse gas emissions.

Animal agriculture also contributes to the emergence of zoonotic pandemics (which are 60% of all pandemic outbreaks). It is hard to know by how much, but the authors of this ebook estimate 70% of zoonotic diseases come from industrial animal agriculture (with uncertainly 50% - 90%). Also, see this article on the subject by Liz Specht from GFI.

I am very uncertain about this, but potentially, eating meat could also increase the chances of a global power conflict over resources like land, water, and energy because animal products require much more of these resources per calorie of food.

Also, I wonder if antibiotic resistance could increase the chances of an existential pandemic caused by airborne bacteria (something like an extremely contagious and extremely deadly version of multidrug-resistant tuberculosis). If that is the case, then eating meat would probably make this worse since the use of antibiotics in farm animals is a significant contributor to the spread of antibiotic resistance. Again, I'm very uncertain here - it's just a thought.

Michael St. Jules posted a link to this post on Facebook and I wrote a reply (formulating it rather quickly I might add), and Peter Hurford suggested that I should copy and paste this reply as a response on the EA Forum, which I am now doing. These thoughts were hastily formulated and are highly fallible and critical feedback is entirely welcome.

" Thinking about the future a million years from now, moral circle expansion is clearly an extremely important concern (failure of moral circle expansion could be catastrophic, and could have catastrophic negative consequences both in terms of causing harm and failing to prevent harm, with each one of those by itself outweighing all gains to positive human well-being, under any plausible non-speciesist moral theory).

Achieving moral circle expansion earlier on plausibly has positive flow-on effects which exponentially grow over time, since if the attainment of complete non-speciesism by the human community occurs one day sooner, then the harm thereby prevented may be such that under other scenarios harm not prevented would have exponentially grown. So, one million years from now, positive flow-on effects from achieving moral circle expansion one day sooner could be significant. So a very strong imperative to work on moral circle expansion as soon as possible right now, including psychologically undermining one's own natural tendency towards speciesism and signalling to others that one is doing so, as long as there are no substantial costs to doing so.

Costs of being vegan are in fact trivial, despite all the complaining that meat-eaters do about it. For almost everyone there is a net health benefit and the food is probably more enjoyable than the amount of enjoyment one would have derived from sticking with one's non-vegan diet, or at the very least certainly not less so. No expenditure of will-power is required once one is accustomed to the new diet. It is simply a matter of changing one's mind-set. The flow-on effects of signalling a strong commitment to non-speciesism to those in one's immediate circle are highly positive. Some complain that one must pay a social cost. Sure, I found that too at least at first, but twenty years later my friends all highly respect me for sticking to my guns. In any case, the fact that there is a social cost to be paid is precisely the point: this is the thing that must be fought against. The tables need to be turned so that it is meat-eaters who feel on the defensive.

From long-termist considerations, the case for going completely vegan starting today, for almost everyone, unless you have some significant reason to believe you would be at risk of major health problems (which is statistically rare indeed), is very strong. "

Full disclosure, not in original FB post: Over 25 years of being vegan, I have occasionally, like Brian Tomasik, deviated from full vegan purity and been just lacto-vegetarian for a while. I now think that this is on the whole not justified.

> Costs of being vegan are in fact trivial, despite all the complaining that meat-eaters do about it. For almost everyone there is a net health benefit and the food is probably more enjoyable than the amount of enjoyment one would have derived from sticking with one's non-vegan diet, or at the very least certainly not less so. No expenditure of will-power is required once one is accustomed to the new diet. It is simply a matter of changing one's mind-set.

Appreciate some of the points, but this part seems totally disconnected from what people report along several dimensions.

I admit I probably should check out whether I can empirically substantiate it. I'm generalising from the experience of myself and my wife and a lot of the long-term vegans that I know. But if in the broader population of people who attempt to be vegan it's not reported as true, well okay first I should try to find out why that's the case and then also understand why it's the case.

> a lot of the long-term vegans that I know

It sounds like you may have a sampling bias, where you're missing out on all the people who disliked being vegan enough to stop?

https://faunalytics.org/a-summary-of-faunalytics-study-of-current-and-former-vegetarians-and-vegans/ has "84% of vegetarians/vegans abandon their diet" which matches my experience and I think is an indication that it's pretty far from costless?

FWIW, the rate was ~50% for vegans who were motivated by animal protection, and ~70% for vegetarians (including vegans) who were motivated by animal protection, based on table 17 on p.18 here. For vegans who were motivated by animal protection, here's the recidivism rate calculation: 0.27×129/(0.62×53+0.27×127)≈0.52≈50% The recidivism rate was about 84% of vegetarians motivated by health, who made up more than half, and 86.6% for vegetarians not motivated by animal protection. Actually, only 27% of former vegetarians and 27% of former vegans were motivated by animal protection, even though those motivated by animal protection make up 70% and 62% of current vegetarians and current vegans, respectively. Also see Tables 9 and 10. I don't think it's surprising that people who go veg*n other than for animals go back to eating meat. It could be evidence of some cost, but it could also mainly be evidence that most people who go veg*n do so for reasons they eventually no longer found compelling, so even small costs would have been enough to bring them back to eating meat. They also go over difficulties people had with their diets in that study, too, though.
Jeff Kaufman
I wonder how much we can trust people's given reasons for having been veg? For example, say people sometimes go veg both for health reasons and because they also care about animals. I could imagine something where if you asked them while they were still veg they would say "mostly because I care about animals" but then if you ask them after you get more "I was doing it for health reasons" because talking about how you used to do it for the animals makes you sound selfish?
Do you have thoughts on what would account for the variance in degree of dislike of the diet, then?
I think the Faunalytics studies discuss this. I think why people were vegetarian/vegan in the first place is a big factor, since the recidivism rate for vegans motivated by animal protection was only about 50%. See my other comment.
This is a great research question IMO
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How do longtermists feel about punching their neighbor in the face? Are there any fleshed-out, longtermist arguments out there on why people shouldn't punch their neighbor in the face?

"With this framework, we can propose a clearer answer to the moral offsetting problem: you can offset axiology, but not morality." https://slatestarcodex.com/2017/08/28/contra-askell-on-moral-offsets/

Assuming the harm of both actions to be equal, this is only really a fair comparison if eating meat and punching your neighbour is equally costly.

I'd argue that not-eating-meat is costly, and not-punching-your-neighbour is cheap (or personally beneficial) in the medium to long run. (That deciding not to eat meat is currently costly sucks and should be changed.)

Peter's point is that it makes a lot of sense to have certain norms about not causing serious direct harm, and one should arguably follow such norms rather than expecting some complex longtermist cost-benefit analysis.

Put differently, I think it is very important, from a longtermist perspective, to advance the idea that animals matter and that we consequently should not harm them (particularly for reasons as frivolous as eating meat).

I don't think that calling meat-eating frivolous is very helpful.
Most vegans revert to consuming some degree of animal products (as far as I understand the research they end up eating meat again, but in lower quantities), indicating that there are significant costs involved.

A side-constraint about harm is generally plausible to me.
I'm still somewhat sceptical about the argument:
- Either you extend this norm to not ommiting actions that could prevent harm from happening, or you seem to be making a dubious distinction between acts and omissions. Extending the norm would possibly give reasons for longtermists to prioritise other ways to prevent harm over not eating meat (and then this should be part of the longtermist cost-benefit-analysis the OP asks for).
- There should be some way to account for the fact that in some cases violating the side-constraint is costly, while in other cases complying with the side-constraint is costly.

I completely agree that longtermists should take animal welfare into account, and that is not happening to an adequate degree at the moment. I'm far less sure, whether comparing meat-eating to punching your neighbour is going to achieve this.

I claim cost of not-eating-meat is drastically over-estimated. Have you tried it?

Hey Rupert

[I just want to clarify that, of the large existing diets, I think that vegans probably have the morally best diet. I also don't want to discourage anyone from becoming vegan or vegetarian. I just want to somewhat push back at the idea that being vegan comes at trivial personal costs.]

Yes, I was vegetarian for around 5 years, 2 of which I was vegan. I've since become what you might call reducetarian (of which no chicken or pork, mainly milk, sometimes beef and eggs).

Personally, I can say that the costs of transitioning are quite high. I guess that during the whole transition it took me around 30 to 150 hours of work, which I wouldn't have had with a standard diet (it's hard to quantify in retrospect and depends on how you define work). But transitioning has also quite some fun aspect, restricting your diet forces your creativity, you get to know new people etc. So I'd say that costs of transitioning are hard to evaluate.

I suspect that I would pay anywhere from $400 to $1200 per year from my non-altruistic budget to keep my standard diet (depending on lots of factors, especially income at the time). The main reasons for reverting were taste, ease and nutritional value. I could well be that my WTP for a standard diet is higher than average. I also suspect that this cost estimate will dramatically decrease over the next years as vegan products become tastier and more available, and this could very well mean I'll become vegan again.

For some people, like Michael, the costs involved appear to be rather small. But it doesn't seem very plausible that 84% of vegans, or so, revert to consuming animal products if they typically perceive the cost of not eating meat to be only $100 per year (let's say adjusted to an average american income).

One bad aspect of the vegan movement is the insistance that personal costs are very small. Claims that are often made circle around "You won't miss the taste of animal products after a while.", or "Having a healthy vegan diet is easy.". I believe that both these points are simply untrue for many people.

I think we have good reason to believe veg*ns will underestimate the cost of not-eating-meat for others due to selection effects. People who it's easier for are more likely to both go veg*n and stick with it. Veg*ns generally underestimating the cost and non-veg*ns generally overestimating the cost can both be true.

The cost has been low for me, but the cost varies significantly based on factors such as culture, age, and food preferences. I think that in the vast majority of cases the benefits will still outweigh the costs and most would agree with a non-speciesist lens, but I fear down-playing the costs too much will discourage people who try to go veg*n and do find it costly. Luckily, this is becoming less of an issue as plant-based substitutes are becoming more widely available.

My impression is that people do over-estimate the cost of 'not-eating-meat' or veganism by quite a bit (at least for most people in most situations). I've tried to come up with a way to quantify this. I might need to flesh it out a bit more but here it is.

So suppose you are trying to quantify what you think the sacrifice of being vegan is, either relative to vegetarian or to average diet. If I were asked what was the minimum amount money I would have to have received to be vegan vs non-vegan for the last 5 years if there were ZERO ethical impact of any kind, it would probably be $500 (with hindsight - cue the standard list of possible biases). This doesn't seem very high to me. My experience has been that most people who have become vegan have said that they vastly overestimated the sacrifice they thought was involved.

If one thought that there were diminishing returns for the sacrifice for being vegan over vegetarian, perhaps the calculus is better for being vegetarian over non-vegan, or for being vegan 99% of the time, say only when eating at your grandparents' house. I see too many people say 'well I can't be vegan because I don't want to upset my grandpa when he makes his traditional X dish'. Well, ok, so be vegan in every other aspect then. And as a personal anecdote, when my nonna found out she couldn't make her traditional Italian dishes for me anymore, she got over it very quickly and found vegan versions of all of them [off-topic, apologies!].

I also suspect that people are comfortable thinking about longtermism and sacrifice like this for non-humans but not for humans is because they may think that humans are still significantly more important. I think this is the case when you count flow-on effects, but not intrinsically (e.g. 1 unit of suffering for a human vs non-human).

I think the intrinsic worth ratio for most non-human animals is close to 1 to 1. I think the evidence suggests that their capacity for suffering is fairly close to ours, and some animals might arguably have an even higher capacity for suffering than us (I should say I'm strictly wellbeing/suffering based utilitarian in this).

I think the burden of proof should be on someone to show why humans are significantly more worthy of intrinsic moral worth. We all evolved from a common ancestor, and while there might be a sliding scale of moral worth from us to insects, it seems strange for there to be such a sharp drop off after humans, even within mammals. I would strongly err on the side of caution when applying this to my ethics, given our constantly expanding circle of moral consideration throughout history.

Eliezer Yudkowsky wrote a sequence on ethical injunctions where he argued why things like this were wrong (from his own, longtermist perspective).

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