Monday 16 January 2012

Partial and General food equilibria

I'm omnivorous, mostly because I enjoy the taste of meat. I can rationalize it ethically by looking at Cowen's argument that it's ok, so long as the eaten animal had enjoyed positive lifetime utility and wouldn't have existed but for my willingness to subsidise its existence in exchange for later being able to eat it. But I know that that argument also rationalizes baby farming to produce slaves for me*. And there are other problems in bringing animals under a utilitarian framework. And so I try not to think about it too much. Because animals are tasty. And a vegetarian diet would be a big hassle. And I am indeed made happier by thinking about lambs playing in paddocks who wouldn't get to exist but for my eating them. So I follow Cowen's rule and aim for animals I can imagine enjoyed positive lifetime utility.

Vegetarians sometimes argue** that we have to abandon meat-eating because meat is an inefficient way of generating calories: if we all scaled up to Western diets, there wouldn't be enough land to grow food for everybody unless we switched over to vegetarian diets.

That argument is wrong on two fronts.

First, some land does most efficiently generate calories by producing grass to be eaten by animals. Like New Zealand high country sheep farming. There's not enough water in the country to irrigate that land to make it suitable for cropping. But it'll support low-density pastoral agriculture. Further, some grain crops wind up being of low value for human consumption but still suitable as supplement for animals. So the optimum is unlikely to involve everyone switching to vegetarianism if the objective is maximizing total available calories for human consumption (though if the developed world's bigger problem is obesity, I'm not entirely sure why we ought to take this as maximand anyway).

Second, it's entirely a partial equilibrium story. What happens as folks in the third world get richer and start moving from inferior goods like lentils and rice to superior goods like beef and lamb? The price of the latter get bid up. And what happens when relative prices change? People change their consumption bundles. And so I find the Washington Post reporting that Americans are eating less meat as meat prices increase.
Why is this happening? The Daily Livestock Report blames rising meat prices in the United States. As countries like China and India get richer, they’re eating more meat, which is helping to drive up U.S. exports and making beef, pork, and chicken more expensive here at home. Ethanol also plays a role: Nowadays, American farmers divert bushels and bushels of corn to make fuel, which drives up feed prices and, again, makes meat pricier.
There's no need for a moral imperative to reduce meat-eating. Get rid of subsidies in the agricultural sector, make sure effluent externalities are properly priced or regulated, then let relative price adjustments take care of the rest. The optimal amount of meat will be eaten, so long as we keep waving our hands about the moral questions.

* You can maybe square this by saying people get massive disutility from being slaves while animals don't know that they're slaves. But humanity has a long history of slavery, and most slaves, as best I'm aware, didn't commit suicide. So by revealed preference, lifetime utility was likely still positive. And then we're stuck again.

**This was somewhat sparked by an argument on Google Plus linked here (thanks Ryan!) which I cannot figure out how to link.

19 comments:

  1. So which animals are most likely to have enjoyed positive lifetime utility? (I'm guessing sheep from the above.)

    Looks like the US made at least a little progress towards removing some subsidies this year -- Congress inexplicably allowed the ethanol credit to expire in an election year

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    1. Anything pastured, feedlot beef if the stocking density isn't too high, dairy if the animals get time outside. Not caged chickens.

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  2. Apparently you get vitamin B12 from red meat, organ meats, eggs and milk. With small amounts from certain vegetables and beans, but so small that you still require a vitamin supplement to avoid vitamin deficiency. So turns out it isn't all that "natural" to be a strict vegan. I guess it could be possible for the world to become vegetarians that consume lots of eggs and milk though.

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    1. We wouldn't have pointy incisors if eating meat weren't biologically natural for us.

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  3. Btw, is this the Google-plus conversation you were looking for? (I hope that link works)

    https://plus.google.com/107475727645912993113/posts/S58YNvc44dT

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  4. It's not an argument that you can win though Eric because you are arguing against people that are more interested in their particular ideology than fact. It's like trying to convince a fundamentalist christian that evolution is a better theory to explain the biological diversity on our planet - they aren't interested in evidence.

    AFAIK it is a fairly commonly held belief amongst evolutionary biologists that the move to an omnivorous diet containing a significant amount of meat was one of the key factors in the rapid increase in brain size among early hominids, leading to the gradual development of Homo sapiens. Without the extra nutrition (proteins, fats, etc) gained from eating yummy animals we may still be naked and hairy, crawling around on the savannah digging up roots and foraging for berries, picking lice off each other.

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    1. Thing is, I'm happy enough with the folks who actually are religious about it and just say it's wrong to eat meat. That's not crazy. Most of us reckon cannibalism is wrong; the line should probably push back to animals that are at least as intelligent as the least intelligent person - dolphins, elephants, maybe octopus.

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    2. So what you are saying is that, thanks to Creationists, we are only allowed to eat the stupider legumes?

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    3. @Eric - Fair enough. I think I'd feel a bit uneasy if somebody offered me a plate of chimpanzee, but I'd also turn up my nose at dog or cat, although not for any reason other than I like dogs and cats, and would feel weird about eating something that would normally be a pet. However the same prejudice doesn't extend to horse, which I haven't eaten, but would happily chow down on, no doubt much to the horror of the horse lovers out there.

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    4. @Kimble: I didn't say anything about "allow"; I said I'd draw my own line about whether an animal ought be eaten based at least partially on the animal's capacity for self-awareness, sentience, etc. But I fear I could never give up bacon even if somebody does someday prove pigs to be more intelligent than we reckon.

      @Lats: Food norms are complicated.

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  5. You should ask Eli how his Paleo/Ancestral diet is going. Gary Taubes is also a source of lots of information on this new approach to thinking about food. Look out for his EconTalk (or fellow economist Arthur DeVany's talk). Still a lot of evidence to gather but it would be a real about face if the solution to obesity was more meat (or at least less sugars with it).

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    1. If I had any weight/health problems, I'd go paleo-ancestral before anything else. I'm not that far from paleo on average most of the time anyway; my main weight problem is avoiding weight loss. I only eat things I reckon are tasty, but that doesn't put me crazy far from paleo anyway. Hence my problem in keeping weight on.

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  6. If we assume that most people would get significantly more psychic disutility from the knowledge you are raising baby slaves vs. eating animals, then it works out. Though, I don't really like psychic utility arguments because you can use them to pretty much assume any conclusion you want. ("The Holocaust was utility-enhancing because the psychic utility to the Nazis was greater than the costs to others"). Then again, I suppose it's an issue with utilitarianism in general, you just have to draw some kind of line for patently silly utility judgements.

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    1. Psychic externalities are one reason I really like Buchanan/Stubblebine's distinction between potentially Pareto relevant externalities and ones that are actually Pareto relevant. If the Nazis really valued the Holocaust that much, they would have been able to pay their victims sufficiently to make the whole thing happen voluntarily. Use of force says that they violated Pareto.

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    2. Not if Nazi enjoyment of the Holocaust would be substantially diminished with the knowledge that their victims were getting paid. It's like assuming prostitution is always a substitute for rape.

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    3. The null ought be that psychic externalities don't exist; evidence of payment is sufficient to overcome the null. Losses that way are bounded; losses from mistakenly accepting a lunatic's psychic utility claims are potentially unbounded. Robust policy is to ignore them.

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  7. Doesn't that pretty much rule out the case for government intervention for any externality? If there's Coasian bargaining taking place, it's a good sign that no government intervention is necessary.

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    1. It doesn't rule out every case. We can presume, when we see real and obvious external costs being imposed with diffused bearers of the cost, that transactions costs are probably getting in the way of things. Like when the dairy farmer dumps effluent into the ditch and makes a mess of Lake Ellesmere. The harms are pretty obvious. But if I just start claiming that the Beehive's particular shade of beige imposes a trillion dollar's worth of psychic costs on me and that it's consequently efficient to repaint it blue, folks ought to be pretty sceptical.

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