# reallyeli comments on What is the current best estimate of the cumulative elasticity of chicken?

• Thanks, Sa­mara. I found the pa­per you’re talk­ing about here: https://​​www.ncbi.nlm.nih.gov/​​pmc/​​ar­ti­cles/​​PMC2804646/​​pdf/​​216.pdf

I’m out of my depth here, but it looks like the pa­per is an­swer­ing the ques­tion: “if the price of chicken changes from \$X/​kg to \$(X + Y)/​kg, how will kg of chicken sold change?” While the ques­tion I’m ask­ing is “if I don’t buy chicken, how will kg of chicken sold change?”.

• Thanks for the clar­ifi­ca­tion, I un­der­stand your ques­tion now. You’re ask­ing about es­ti­mat­ing the size of a de­mand shift that re­sults from one eco­nomic agent leav­ing the mar­ket, as op­posed to an elas­tic­ity. I be­lieve we’re ask­ing the same ques­tion; with elas­tic­i­ties, I want to in­ves­ti­gate the un­der­ly­ing mechanism that takes us from your leav­ing the mar­ket to a shift in the de­mand curve. Whereas you would like to know the end re­sult only.

The an­swer to this ques­tion (the effect on ag­gre­gate de­mand of one per­son leav­ing the mar­ket) may be difficult to es­ti­mate cor­rectly. The best ap­prox­i­ma­tion I can think of in the ex­ist­ing liter­a­ture is the effect of food scares on de­mand. For ex­am­ple, this pa­per on news cov­er­age of salmonella out­breaks and this pa­per on me­dia cov­er­age of the BSE (mad cow) out­break on de­mand for Bri­tish beef both show the im­pact on de­mand of me­dia cov­er­age of food scares. Of course, they have to use a me­dia cov­er­age as a proxy for peo­ple leav­ing the mar­ket, since there’s no way to col­lect data in that way.

Cir­cling back to your friend’s ques­tion, I do think that it’s un­likely that you or an­other in­di­vi­d­ual leav­ing the mar­ket would af­fect price enough to trig­ger in­creased pur­chases in the peo­ple re­main­ing. I sus­pect that you leav­ing the mar­ket would also have a very small effect on ag­gre­gate quan­tity de­mand, in the same way that your marginal non-pur­chase of chicken will be un­likely to change the way that the su­per­mar­ket or­ders their prod­ucts. Similarly, just you en­ter­ing the mar­ket for meat al­ter­na­tives won’t cause a large in­crease in de­mand. I do think your dis­cus­sion with your friends will plant some seeds, though.

• I like the idea of us­ing food scares as a proxy! Very cool.

It sounds like you are say­ing that know­ing “how will kg of chicken sold change given change in price” will let you an­swer “how will kg of chicken sold change given me not buy­ing chicken.” I don’t see quite how to do this, could you give me a poin­ter? (for con­crete­ness, what does the pa­per’s es­ti­mate of elas­tic­ity of poul­try at 0.68 mean for “kg of chicken sold given I don’t buy the chicken”)

Per­haps more im­por­tantly, it sounds like you might dis­agree that one per­son ab­stain­ing from eat­ing chicken has a mean­ingful im­pact on the num­ber of chick­ens raised + kil­led. If so I’m quite in­ter­ested, as this is some­thing I have be­come con­vinced against by sources like https://​​re­duc­ing-suffer­ing.org/​​does-veg­e­tar­i­anism-make-a-differ­ence/​​.

My cur­rent model is that if I buy the meat of one chicken at a su­per­mar­ket, that *in ex­pec­ta­tion* causes about one chicken to be raised + kil­led.

• Sure, I didn’t dis­cuss the con­nec­tion be­tween your de­mand de­crease and the re­main­ing peo­ple’s elas­tic­i­ties. Let’s use Brian’s ex­am­ple of the su­per­mar­ket sup­ply sys­tem to illus­trate that con­nec­tion.

When you stop buy­ing chicken, de­mand in the store has de­creased. Per­haps it de­creases to the point where the store de­cides to put the chicken on sale. Other shop­pers who still buy meat will see the sale price and change their pur­chases ac­cord­ing to their price ela­sic­i­ties, which are defined as the per­cent change in quan­tity de­manded given a 1% change in price. Us­ing the spe­cific ex­am­ple of the pa­per’s elas­tic­ity, a 1% de­crease in price would cause a shop­per to buy 0.68% more chicken. In the next or­der­ing cy­cle, the in­ven­tory man­ager or­ders less chicken be­cause you de­cided not to buy chicken and be­cause the other shop­pers pur­chased some of the ex­cess stock at the sale price. We could call this a new equil­ibrium, and we see that equil­ibrium quan­tity de­mand has shifted. I won’t make an as­sump­tion on whether the equil­ibrium price is lower in this lit­tle su­per­mar­ket sce­nario (only be­cause I’m not sure how su­per­mar­kets ac­tu­ally set their prices).

Th­ese causal path­ways are always a lit­tle tricky be­cause you can always talk your way out of any sce­nario, but the un­der­ly­ing mechanism be­hind a de­mand shift in a larger, more ab­stract mar­ket could work like this.

This hy­po­thet­i­cal su­per­mar­ket brings up your sec­ond point. You’re right for call­ing me out on my state­ment about not mak­ing a differ­ence—your non-pur­chase of meat in a gro­cery store does have the prob­a­bil­ity of set­ting off a chain re­ac­tion in the sup­ply chain that re­duces the num­ber of chick­ens kil­led in ex­pec­ta­tion. I should have been more clear in my pre­vi­ous com­ment, be­cause I was cer­tainly think­ing of a larger-scale ag­gre­gate mar­ket like, for ex­am­ple, the en­tire US mar­ket for chicken. In this case, you are one of ~300m peo­ple in the mar­ket for chicken, and your one-time non-pur­chase would have a small effect that would be hard to es­ti­mate (this is a more pre­cise state­ment of what I meant).

I do be­lieve that you save may chick­ens, in ex­pec­ta­tion, with a non-pur­chase. And fur­ther, I do be­lieve that your con­tinued non-pur­chase of chicken and your en­try into the al­ter­na­tives mar­ket will, in ex­pec­ta­tion, save more chick­ens. I also be­lieve that your non-pur­chase of chicken will likely lead you to change other pur­chas­ing de­ci­sions ac­cord­ing to your ethics, and I be­lieve that your eth­i­cal de­ci­sions will, in ex­pec­ta­tion, in­fluence the peo­ple around you. (This is also some­thing I’d like to study for­mally in the fu­ture.) So I be­lieve, in ex­pec­ta­tion, you can do a lot of good!