Does Vegetarianism Make a Difference?

One common charge against vegetarianism is that abjuring the consumption of factory-farmed animal products will not actually have a real-world impact. Indeed, this is the argument of last resort for those who come to recognize the suffering that factory farms cause yet refuse to change their diets accordingly. In this essay, I endeavor to challenge this point.

Let us first examine the logic behind the position that abstention from factory-farmed products is not morally implied by concern for animals. Everyone in the debate agrees that, at some point, a substantial decrease in demand for meat--for instance, conversion to vegetarianism by half of the US population---would diminish the quantity supplied of factory-farmed animals. "That's great," argues the opponent of vegetarianism, "but it has nothing to do with individual purchasing habits. The only decisions that will actually affect the amount of animal suffering are massive investment choices: whether to build a new factory farm or whether to put an addition on a colossal chicken house. One consumer cannot even change the bulk purchases that each individual grocery store or dining center makes, much less the collective demand that all of these retailers exert. So I can continue to eat meat without creating demand for the production of any more animals. A certain amount of meat will be produced whether I am vegetarian or not, so why shouldn't I at least subsist off those excess scraps, instead of letting them go to waste?"

Suppose that a supermarket currently purchases three cases per week of factory-farmed chicken wings. The store does not purchase fractions of cases, so even if several surplus wings remain on the shelves each week, the supermarket will continue to buy three cases. This is what the anti-vegetarian means by "subsisting off of surplus animal products that would otherwise go to waste": the three cases are purchased anyway, so consuming one or two more chicken wings simply attenuates the surplus.

What would happen, though, if 200 customers decided to buy tempeh or beans instead of chicken wings? The purchasing agent who orders weekly cases of wings would probably buy two cases instead of three. At some point between a lowered demand of 0 wings and 200 wings, the purchasing agent made the decision to order one less case; however, it's impossible to determine exactly where the dividing line will be. The agent's decision may be arbitrarily based on approximately how many wings the store appears to have at the moment, and it is impossible to know ahead of time whether that arbitrary judgment will be made between the 36th and 37th wing that isn't demanded, or between the 182nd and 183rd wing. But somewhere, that dividing line exists. (I do not know exactly how ordering decisions are made at supermarkets and retail stores; perhaps they are based on historical data of consumption levels at various times of the year. But regardless of the detailed procedure, the point is that they are based in some way on the actual amount of products purchased.)

Not only does any given consumer not know the number of the wing that will determine how many cases the supermarket buys; she also does not know the number of the wing that she is purchasing, because she has no way of knowing how many other consumers like her happen--for whatever reason--to be demanding fewer wings as well. So even if she could establish that the supermarket would not buy one case fewer until consumers bought 400 fewer wings, she would have no way of knowing whether the individual wing that she refrains from purchasing is that 400th wing or--what is more likely---whether her refusal to buy an earlier wing will cause someone else to be the 400th person not to buy a wing.

The same logic applies in reverse to the "subsistence from surplus" excuse. The critic of vegetarianism claims that the supermarket would buy three cases of chicken wings per week anyway, regardless of whether he himself buys one wing and lowers the store's surplus waste from 18 to 17. But at some point--at some minimum level of surplus or deficit--the store's purchasing agent will choose to buy four cases instead of three. As before, any individual consumer has no way of knowing at which wing number that change will occur or which number wing he happens to be buying.

Assume it takes 200 fewer consumers of chicken wings in order for the supermarket to buy one less case. Inasmuch as individual consumers have no way of telling whether their particular wing will be the one that changes the number of cases purchased, the probability of any given carton being the determining factor is 1/200. The expected value of an action is the probability that a benefit will result times the magnitude of the benefit if it does result, so the expected value of refraining from the purchase of any given carton of milk is (1/200)(1 fewer case purchased)(200 wings/case) = 1 fewer wing purchased. The exact expected values will of course fluctuate on account of the randomness of the purchasing agent's decisions (if, for instance, she would not buy one fewer case until 300 fewer consumers demanded wings, even though each case includes only 200 wings), but they should average out over the long run in such a way that forbearing the purchase of any given amount of an animal product will be expected to reduce bulk purchase of that amount of the product.

This logic applies also to the rest of the factory-farmed-meat demand process: at some critical mass of fewer cases ordered by stores, distributors will purchase fewer chicken wings from farms, and that reduced demand from farms will, at some point, constrict production. By the end, the probability that any given consumer will impact animal production is miniscule, but the benefits if he does are immense. Thus, the expected value of refraining from the purchase of any given amount of an animal product is roughly equivalent to preventing the production of the portion of an animal that the product represents. Of course, it is entirely possible (perhaps even likely) that a vegetarian may go through her entire life and never, by failing to purchase factory-farmed animal products, have actually prevented any animal suffering by lowering production. But because she has no way of knowing when the special purchase that does set off the chain of significant demand reduction will be, she has to act as if every purchase does count. (For more on this, see "Instrumental Judgment and Expectational Consequentialism.") And for all she knows, she may just as easily be a consumer who has more than her share of impact on demand for factory-farmed products.

The actual expected amounts of suffering prevented vary widely by the type of animal product avoided. Avoiding purchase of a chicken prevents roughly six weeks of direct suffering by a broiler hen. Avoiding purchase of a dozen eggs directly prevents 12.5 days of suffering by a battery-cage hen (not counting the suffering of male chicks that may be ground up). Avoiding purchase of a half-gallon (1.89-liter) carton of milk prevents between 2.3 and 2.8 hours of suffering for a milk cow, ignoring the effect on her calf (this assumes a cow produces 16-20 liters of milk in a day). For more, see "How Much Direct Suffering is Caused by Various Animal Foods?"

While the mechanism described above for the impact of vegetarianism may apply to most cases, there are some situations in which the demand-reduction benefits of abstaining from animal products are less likely to materialize. The most notable example might be a party or picnic to which--despite one's best efforts--people have brought hot dogs and hamburgers. The purchasing decisions of a supermarket may be imprecise and sometimes arbitrary, but they will eventually be affected if demand changes by a great enough amount. The same can not be said of those who purchase items for a picnic. In general, the purchaser will buy some overestimated amount of food beforehand, regardless of how many people actually consume those comestibles at the event. And whereas a store that purchases far too much of a product will keep records and change its behavior the next time, people buying picnic food probably will not. So it is unlikely that one's decision to eat or refrain from eating a factory-farmed-animal product at an informal social gathering will make much difference to the amount of food that the organizer purchases the next time. (Perhaps the best way to limit the harm done by a picnic is to ask the purchaser ahead of time to buy less meat.)

I should add, however, that to the extent non-vegetarians take home and actually consume left-overs from a social event, they may thereby reduce the amount of food they buy in the future, including meat products. In fact, this effect may be sometimes true even for non-meat leftovers. The lesson is, then: If you have leftovers, give them to the person who's most likely to buy meat for his own meals. The situation may differ if, by taking the leftovers yourself, you save money that you can then donate to prevent suffering in other ways.

But even if consuming a hamburger at a picnic would assuredly not change the direct amount of meat purchased, there might still be other good reasons for not doing so. First, people may not realize the extensive reasoning presented above and thence may view a vegetarian's consumption of the hamburger as contradictory (even if it actually is not). This misunderstanding might diminish the respect that others have for the vegetarian in particular and for the cause of vegetarianism in general. (Perhaps the vegetarian would unintentionally be showing how hard it is to maintain his diet, thereby discouraging others from trying.) Second, avoiding animal products can raise the topic of factory farming. This, indeed, is one of the most important consequences of being a vegetarian in any context, for good discussions--combined with the literature exchange or further research that might follow--have the potential to permanently change other people's eating habits.

Note: This article is very similar to another I've since discovered: "Expected Utility, Contributory Causation, and Vegetarianism" by Gaverick Matheny.