Excerpt from ‘Doing Good Better’: How Vegetarianism Decreases Animal Product Supply

Over the last few years I’ve seen de­bates among EA com­mu­nity mem­bers over whether one’s eco­nomic choices as a veg­e­tar­ian have any effect on the sup­ply of an­i­mal meat pro­duced in in­dus­try. This has always per­plexed me, as Will MacAskill wrote in Do­ing Good Bet­ter about the mechanism by which veg­e­tar­i­anism is thought to de­crease the sup­ply of meat prod­ucts. While one may agree or dis­agree with the claims Will makes, this ex­cerpt can provide the grounds fram­ing the dis­cus­sion.

Con­sider eth­i­cal con­sump­tion, like switch­ing to fair-trade coffee, or re­duc­ing how much meat you buy. Sup­pose some­one stops buy­ing chicken breasts, in­stead choos­ing veg­e­tar­ian op­tions, in or­der to re­duce the amount of an­i­mal suffer­ing on fac­tory farms. Does that per­son make a differ­ence? YOu might think not. If one per­son de­cides against buy­ing chicken breast one day but the rest of the meat eaters on the planet con­tinue to buy chicken, how could that pos­si­bly af­fect how many chick­ens are kil­led for hu­man con­sump­tion? When a su­per­mar­ket de­cides how much chicken to buy, they don’t care that one fewer breast was pur­chased on a given day. How­ever, if thou­sands or mil­lions of peo­ple stopped buy­ing chicken breasts, the num­ber of chick­ens raised for food would de­crease—sup­ply would fall to meet de­mand. But then we’re left with a para­dox: in­di­vi­d­u­als can’t make a differ­ence, but mil­lions of in­di­vi­d­u­als do. But the ac­tions of mil­lions of peo­ple are just the sum of the ac­tions of many in­di­vi­d­ual peo­ple. More­over, an iron law of eco­nomics is that, in a well-func­tion­ing mar­ket, if de­mand for a product de­creases, the quan­tity of the product that’s sup­plied de­creases. How, then, can we rec­on­cile these thoughts?

The an­swer lies with ex­pected value. If you de­cline to buy some chicken breast, then most of the time you’ll make no differ­ence: the su­per­mar­ket will buy the same amount of chicken in the fu­ture. Some­times, how­ever, you will make a differ­ence. Oc­ca­sion­ally, the man­ager of the store will as­sess the num­ber of chicken breasts bought by con­sumers and de­cide to de­crease their in­take of stock, even though they wouldn’t have done so had the num­ber of chicken breasts bought by con­sumers and de­cide to de­crease their in­take of stock, even though they wouldn’t have done so had the num­ber of chicken breasts been one higher. (Per­haps they fol­low a rule like: “If fewer than five thou­sand chicken breasts were bought this month, de­crease stock in­take.”) And when the man­ager does de­cide to de­crease their stock in­take, they will de­crease stock by a large amount. Per­haps your de­ci­sion against pur­chas­ing chicken breast will have an effect on the su­per­mar­ket only one in a thou­sand times, but in that one time, the store man­ager will de­cide to pur­chase ap­prox­i­mately one thou­sand fewer chicken breasts.

This isn’t just a the­o­ret­i­cal ar­gu­ment. Economists have stud­ies this is­sue and worked out how, on av­er­age, a con­sumer af­fects the num­ber of an­i­mal prod­ucts sup­plied by de­clin­ing to buy that product. They es­ti­mate, on av­er­age, if you give up one egg, to­tal pro­duc­tion ul­ti­mately fassl by 0.91 eggs; if you give up one gal­lon of milk, to­tal pro­duc­tion falls by 0.56 gal­lons. Other prod­ucts are some­where in be­tween: economists es­ti­mate if you give up one pound of beef, beef pro­duc­tion falls by 0.68 pounds; if you give up one pound of pork, pro­duc­tion ul­ti­mately falls by 0.74 pounds; if you give up one pound of chicken, pro­duc­tion ul­ti­mately falls by 0.76 pounds.

MacAskill, William, Ph.D. “Why Vot­ing Is Like Donat­ing Thou­sands of Dol­lars to Char­ity.” In Do­ing Good Bet­ter: How Effec­tive Altru­ism Can Help You Make A Differ­ence, 87-88. New York, NY: Pen­guin Ran­dom House LLC, 2015.

The eco­nomic im­pact of veg­e­tar­i­anism or ve­g­anism is only one fac­tor in the de­ci­sion of whether one should be­come a veg­e­tar­ian or ve­gan, but an im­por­tant one. Fur­ther dis­cus­sion of why to be­come veg­e­tar­ian on eco­nomic grounds within the com­mu­nity can be found here.