Philosophical reflection (TL;DR the punchline is still pretty much "shut up and go vegan")

Recently I looked back through my inbox history to look back on a conversation that I had with my aunt that I thought was quite funny.

"Do you mind if I ask you a legal question.

So I was having a conversation on the newsgroup alt.animals.ethics.vegetarian where we were talking about the amount of harm caused to animals by soybean production, and I said that if you were concerned with trying to reduce the amount of harm suffered by animals then the rational strategy would be to govern your food choices by the criterion of which purchase caused the least marginal expected increase in harm, so in particular in evaluating that for a purchase of a soy-based product, you would have to calculate the amount of harm caused by the production of one hectare of soybeans and then divide that by the number of servings of the product in question that could be produced from growing one hectare. But then someone objected and said that a vegan must consider himself to have responsibility for the full amount of harm caused by the production of the entire hectare even if they only bought one serving of the product. He said that each person who buys one serving of the product created from the production of the hectare of soybeans has responsibility for the full amount of harm caused by the production of the entire hectare.

In an attempt to defend this view, he gave a thought-experiment about five people who plan a bank robbery together. He said that if people were killed in the course of doing the robbery, each person who conspired to do the robbery would be legally culpable for murder even if only one person actually shot anybody. He said it was quite common practice for prosecutors to threaten people who had been charged with armed robbery with additional murder charges on these grounds, in order to get them to co-operate by providing useful information. Is this account of the legal situation correct?"

"Hi Ru,

Sorry for my slow response. I have been on leave. Yes, his analysis is
broadly correct but there is a bit more to it than that.  Legal
responsibility for, say, a killing when something goes wrong during an
armed robbery turns on what is called joint criminal enterprise. But a
critical issue is to know what was within the contemplation of each
participant. If five guys set out to rob a bank and one had a gun and
someone got killed by the gun (say he panicked and shot someone or even if
it fired accidentally) the liability of the others would turn mainly on
whether they knew he had the gun.  The element the crown would have to
prove against each would be whether they contemplated the possibility that
someone would be killed or inflicted with grievous bodily harm.

But that is not to say that this principle applies to the consumption of
soybeans. It is a difficult analogy, I think."

Sharing the conversation for the sake of humour with some friends who have an interest in philosophy, the conversation proceeded to consideration of the topic itself, so I wrote up these notes for them:

"Some thoughts…

“Circle of rightsholders”: it is widely agreed today, perhaps, that there is some class of beings which is a “circle of rightsholders”, including perhaps at least all post-natal human beings with conscious experience, where in some appropriate sense there is some overwhelmingly strong presumption against doing them harm or financially supporting another in foreseeably or deliberately doing them harm assuming that the beings being harmed are “morally innocent” in some suitable sense.

Now, consider the following argument which I shall attempt to critique:

(1) Suppose that you extend your “circle of rights-holders” to include some significant class of conscious non-human animals (for example, at least all mentally normal mammals aged one year or more, as in Tom Regan’s “Case for Animal Rights”, or possibly even all members of animal kingdom who are conscious, as in Gary Francione’s work)
(2) Then you’ll end up with the conclusion that, if you’re a reasonably affluent Westerner living in a modern technological society, the burden involved in totally refraining from financially supporting all processes that foreseeably cause serious harm to being in your circle of right-holders will be so incredibly great that hardly anyone can realistically be expected to put such a view into practice (consider, for example, harm to wild animals in crop fields from plant-based agriculture, harm to wild animals from cotton production, timber production, electricity production, accidentally killing insects while driving if they’re conscious, prescription medications tested on animals)
(3) But an acceptable moral theory has to be such that a significant number of people in our community can actually realistically expected to put such a view into practice
(4) So it’s reasonable to conclude that extending your “circle of rights-holders” beyond the boundary of our own species is therefore misguided, and this undermines the motivation for ethical veganism

Now consider the following response:

(1) There are a number of areas of consumption where you must be foreseeably causing harm or financially supporting foreseeable harm to humans who haven’t consented to bear the risk: deaths from air pollution as a result of driving or electricity production even if we put aside any thoughts about car crashes or anthropogenic climate change, deaths from environmental harm due to cotton production (there is public data on this), enslavement of children and other Third World workers for coffee or chocolate production (literal enslavement, not just poor working conditions due to poverty), financially supporting current on-going military actions by submitting to the legal obligations to pay taxes, if you live in the US at the moment for example, although for that case naturally there are complications from “just war theory”. 
(2) But people who proclaim themselves “advocates of human rights” with apparent sincerity are usually willing to permit themselves at least some of these forms of consumption (or failure to engage in tax resistance) without relaxing their moral opposition to more blatant forms of human exploitation which are currently illegal
(3) So that would suggest that implicit in the common notion of “rights-holder” is some kind of proviso to the effect that you are sometimes permitted to foreseeably cause or financially support harm if the burden of avoiding doing so would be too great, perhaps on the understanding that you may hold out the hope that such avoidable harms may eventually be completely eliminated with further social or technological progress
(4) Therefore the advocate of the human-centric ethic can’t claim that the ethical vegan is  “morally compromised” in a sense which wouldn’t also apply to themselves

While there are further issues to be explored here including perhaps numerical estimates of expected quantity of harm caused, something like this, I think, is the best response to the “collateral deaths from plant agriculture” argument. 

While the empirical question of whether you can actually achieve lower expected harm footprint on a grass-fed beef only diet, following papers are relevant and worth considering:

https://fewd.univie.ac.at/fileadmin/user_upload/inst_ethik_wiss_dialog/Matheny__G._2003_Defense_of_Veg__in_J._Agric_Ethics.pdf
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=1253172
https://philpapers.org/rec/FISFDI

and then finally with regard to this YouTube video which I was asked to comment on

https://www.youtube.com/watch?v=Oq46v2zeEPE

it is totally irresponsible propaganda to suggest that for typical animal products a consumer vegan might have larger expected harm footprint, and the reasoning from basic microeconomics is clear. If you’re regularly buying meat from the supermarket and supporting family-farming or factory-farming animal agriculture, then you’ve got the harm caused by the animal agriculture itself plus the higher expected contribution to the demand curve for crop production, so therefore higher expected contribution to total harm caused by crop production. It’s a complete smokescreen to say “Oh, but most of the crop product is unfit for human consumption”, because when you purchase the plant-based foot product your expected contribution to demand curve for land usage for crop production is smaller than your expected contribution that you get out of buying a product which ends up requiring a larger component of the plant as input, and the mathematics of this is so clear and obvious it shouldn’t even need to be discussed. You have some complications from things like the “elasticity factor” which are explicitly included in the spreadsheets previously created by Animal Charity Evaluators on this topic, but that’s not going to change the final outcome for this particular comparison, given that for just about every animal product the crop inputs per calorie are higher by such a large factor. And the creator of this video absolutely knows this and knows that she is deliberately lying. So be fully aware that there most certainly are people trying to lie to you based on vested financial interests. With regard to the headline of the internet article which we may have all seen circulating around, “Ordering the vegetarian meal? Then there’s more blood on your hands”, again, for similar reasons, a totally irresponsible and misleading headline, which is not to say that there are not important issues to look into here.

But for grass-fed beef which truly is grass-fed only, sure… and that’s not typically the case for what is labelled “grass-fed beef”, no, that stuff to would typically involve six months in a feedlot and therefore still greater crop inputs per calorie than for directly eating plant-based feed, but beef which really and truly is only grass-fed, then okay there is maybe some lack of clarity from existing data about how the comparison works out on the “suffering footprint” dimension, and that’s a current topic of investigation. There’s also the thought that from a rule-consequentialist perspective you can argue that there’s value in taking a firm public stand on never supporting the use of animals as property at all given that it’s basically so incredibly easy to do so, apart perhaps from issues like maybe still needing to buy some prescription medications that were tested on animals or whatever. It’s also a complication worth considering, perhaps, that by reducing the land usage required for your lifestyle, you’re maybe increasing the expected number of wild-animal births and perhaps wild animals have net-negative lives. That too. And you’ve got the consideration about methane emissions from livestock being quite a strong greenhouse gas, although no-one’s ever said that a climate-change argument alone is going to get you an obligation to be strictly vegan, only possibly a moral presumption in favour of reducing, and then finally there’s also the debate about whether David Pimentel in his paper on the water-resources argument against eating beef, was maybe a bit misleading by including rainfall in his figure for total water required. I would not want to hang my hat on a water-resources argument and the issues there are complex, I believe “The Ethics of What We Eat” by Peter Singer explores that in some detail.

Quoting Dan Hooley and Nathan Nobis on this topic,

“If a product is such that (a) its production causes serious and unjustified harms and so is morally wrong, (b) the product can be avoided, (c) avoiding the product would not seriously harm the boycotting individual, (d) there are readily available alternatives to that product, (e) the boycotting individual might benefit from boycotting, (f) the probability that not purchasing or consuming the product will lessen or eliminate the wrongdoing is equal to or greater than the probability that purchasing or consuming the product will lessen or eliminate the wrongdoing, and (g) boycotting will make that individual a member of a morally progressive group that opposes a wrongdoing, then individuals are obligated to not purchase or use that product.”

So I leave you with that thought."