While many people in the effective altruism movement are vegan, I'm not, and I wanted to write some about why. The short answer is what while I'm on board with the general idea of making sacrifices to help others I think veganism doesn't represent a very good tradeoff, and I think we should put our altruistic efforts elsewhere.
There are many reasons people decide to eat vegan food, from ethics to taste to health, and I'm just interested in the ethical perspective. As a consequentialist, the way I see this is, how would the world be different if I stopped eating animals and animal products?
One factor is that I wouldn't be buying animal products anymore, which would reduce the demand for animals, and correspondingly the amount supplied. Elasticity means that if I decrease by buying by one unit I expect production to fall by less than one unit, but I'm going to ignore that here to be on the safe side. Peter Hurford gives a very rough set of numbers for how many continuously living animals are required to support a standard American diet and gets:
- 1/8 of a cow
- 1/8 of a pig
- 3 chickens
- 3 fish
Now, I don't think animals matter as much as humans. I think there's a very large chance they don't matter at all, and that there's just no one inside to suffer, but to be safe I'll assume they do. If animals do matter, I think they still matter substantially less than humans, so if we're going to compare our altruistic options we need a rough exchange rate between animal and human experience. Conditional on animals mattering, averting how many animal-years on a factory farm do I see as being about as good as giving a human another year of life?
- Pigs: about 100. Conditions for pigs are very bad, though I still think humans matter a lot more.
- Chickens: about 1,000. They probably matter much less than pigs.
- Cows: about 10,000. They probably matter about the same as pigs, but their conditions are far better.
- Fish: about 100,000. They matter much less than chickens.
Overall this has, to my own personal best guess, giving a person another year of life being more valuable than at least 230 Americans going vegan for a year.
The last time I wrote about this I used $100 as how much it costs to give someone an extra year of life through a donation to GiveWell's top charities, and while I haven't looked into it again that still seems about right. I think it's likely that you can do much better than this through donations aimed at reducing the risk of human extinction, but is a good figure for comparison. This means I'd rather see someone donate $43 to GiveWell's top charities than see 100 people go vegan for a year.
Since I get much more than $0.43 of enjoyment out of a year's worth of eating animal products, veganism looks like a really bad altruistic tradeoff to me.
Comment via: facebook
Let's say I'm trying to convince someone that they shouldn't donate to animal charities or malaria net distribution, but instead they should be trying to prevent existential risk. I bring up how many people there could potentially be in the future ("astronomical stakes") as a reason for why they should care a lot about those people getting a chance to exist. If they have a strong intuition that people in the far future don't matter, though, this isn't going to be very persuasive. I can try to convince them that they should care, drawing on other intuitions that they do have, but it's likely that existential risk just isn't a high priority by their values. Them saying they think there's only a 0.1% chance or whatever that people 1000 years from now matter is useful for us getting on the same page about their beliefs, and I think we should have a culture of sharing this kind of thing.
On some questions you can get strong evidence, and intuitions stop mattering. If I thought we shouldn't try to convince people to go vegan because diet is strongly cultural and trying to change people's diet is hopeless, we could run a controlled trial and get a good estimate for how much power we really do have to influence people's diet. On other questions, though, it's much harder to get evidence, and that's where I would place the moral worth of animals and people in the far future. In these cases you can still make progress by your values, but people are less likely to agree with each other about what those values should be.
(I'm still very curious what you think of my demandingness objection to your argument above)