I guess the inconsistency that I still can't resolve is:
We agree that animal suffering is bad and I accept the point about the expected utility of one person becoming a vegetarian.
Why is animal suffering just bad enough that you are willing to settle for the expected utility of saving the lives of the number of animals you yourself do not eat? I think my problem is that I have convinced myself that the animal suffering problem is bad enough that I should be an animal rights campaigner or something. I'm not going to do that, and the marginal impact of me becoming a vegetarian still just seems so marginal compared to the impact I could have if I actually focused my energy on activism.
Or, if I become a vegetarian for reasons mostly related to animal suffering, I would want to judge others more harshly for not being vegetarians, which is very poor form in conventional social interactions.
If a shift away from factory farming does occur, I don't think it's going to come from more people like me becoming vegetarians. Cheap, delicious meat grown in vats will have a much greater social effect. Once that happens, I'll become a vegetarian, maybe an annual or semi-annual eater of premium, non-factory farmed meat.
Or, if I become a vegetarian for reasons mostly related to animal suffering, I would want to judge others more harshly for not being vegetarians, which is very poor form in conventional social interactions.
Judging others is about making predictions on their future actions in morally challenging situations. If they eat meat, it's a good predictor that they will eat meat in future, but it doesn't say much about whether they'll jump into the canal to save a drowning child.
I have noticed that among philosophers, vegetarianism of one form or another is quite common. In fact, I became a vegetarian (technically a pescetarian) myself partly out of respect for an undergraduate philosophy professor. I am interested in finding out if there is a similar disproportion in the Less Wrong community.
I didn't request that this go into Yvain's survey because I want more information than just what animal products you do or don't eat; I'd also like to see nuances of the reasons behind your diet. There are a lot more shades than carnivore/vegetarian/vegan - if you want to be a vegetarian but are allergic to soy and gluten, that's a compelling reason to diversify protein sources, for instance. I'd also like to hear about if you avoid any plant foods (if you think they're farmed in a way that's environmentally destructive or that hurts people or if you have warm fuzzy feelings for plants, maybe). Here are some questions that come to mind: