You seem to be assuming that meat farming scales linearly in most respects with the number of people consuming the meat. I'd question that assumption, and assume instead that there are marked threshold effects.
Possibly 1000 people swearing off pork would instead have the effect of driving that same farm to a ruthless cost-cutting program, so that it could keep up its volume by selling at lower prices; this would likely be to the hogs' detriment, since they are the "stakeholders" least likely to raise a politically effective complaint about such changes. And frankly, given what I know of the industry, this is a scarily plausible scenario.
Possibly 1000 people swearing off pork would instead have the effect of driving that same farm to a ruthless cost-cutting program
Quite frankly, I don't think this argument makes sense. Meat factories are already ruthless cost-cutting programs, and hogs "complaints" are already not taken into account.
What you seem to be implying here is that if meat farming is bad, we should better give them money so they don't make it even worse.
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: