Effective Altruism Through Advertising Vegetarianism?

Ab­stract: If you value the welfare of non­hu­man an­i­mals from a con­se­quen­tial­ist per­spec­tive, there is a lot of po­ten­tial for re­duc­ing suffer­ing by fund­ing the per­sua­sion of peo­ple to go veg­e­tar­ian through ei­ther on­line ads or pam­phlets. In this es­say, I de­velop a calcu­la­tor for peo­ple to come up with their own es­ti­mates, and I per­son­ally come up with a cost-effec­tive­ness es­ti­mate of $0.02 to $65.92 needed to avert a year of suffer­ing in a fac­tory farm. I then dis­cuss the method­olog­i­cal crit­i­cism that mer­its skep­ti­cism of this es­ti­mate and con­clude by sug­gest­ing (1) a guarded ap­proach of putting in just enough money to help the or­ga­ni­za­tions learn and (2) the need for more stud­ies should be de­vel­oped that ex­plore ad­ver­tis­ing veg­e­tar­i­anism in a wide va­ri­ety of me­dia in a wide va­ri­ety of ways, that in­clude de­cent con­trol groups.



I start with the claim that it’s good for peo­ple to eat less meat, whether they be­come veg­e­tar­ian—or, bet­ter yet, ve­gan—be­cause this means less non­hu­man an­i­mals are be­ing painfully fac­tory farmed. I’ve defended this claim pre­vi­ously in my es­say “Why Eat Less Meat?”. I rec­og­nize that some peo­ple, even those who con­sider them­selves effec­tive al­tru­ists, do not value the well-be­ing of non­hu­man an­i­mals. For them, I hope this es­say is in­ter­est­ing, but I ad­mit it will be a lot less rele­vant.

The sec­ond idea is that it shouldn’t mat­ter who is eat­ing less meat. As long as less meat is be­ing eaten, less an­i­mals will be farmed, and this is a good thing. There­fore, we should try to get other peo­ple to also try and eat less meat.

The third idea is that it also doesn’t mat­ter who is do­ing the con­vinc­ing. There­fore, in­stead of con­vinc­ing our own friends and fam­ily, we can pay other peo­ple to con­vince peo­ple to eat less meat. And this is ex­actly what or­ga­ni­za­tions like Ve­gan Outreach and The Hu­mane League are do­ing. With a cer­tain amount of money, one can hire some­one to dis­tribute pam­phlets to other peo­ple or put ad­ver­tise­ments on the in­ter­net, and some per­centage of peo­ple who re­ceive the pam­phlets or see the ads will go on to eat less meat. This idea and the pre­vi­ous one should be un­con­tro­ver­sial for con­se­quen­tial­ists.

But the fourth idea is the com­pli­ca­tion. I want my philan­thropic dol­lars to go as far as pos­si­ble, so as to help as much as pos­si­ble. There­fore, it be­comes very im­por­tant to try and figure out how much money it takes to get peo­ple to eat less meat, so I can com­pare this to other es­ti­ma­tions and see what gets me the best “bang for my buck”.

Other Estimations

I have seen other es­ti­mates float­ing around the in­ter­net that try to es­ti­mate the cost of dis­tribut­ing pam­phlets, how many con­ver­sions each pam­phlet pro­duces, and how much less meat is ate via each con­ver­sion. Brian To­masik calcu­lates $0.02 to $3.65 [PDF] per year of non­hu­man an­i­mal suffer­ing pre­vented, later $2.97 per year, and then later $0.55 to $3.65 per year.

Jess Whit­tle­stone pro­vides statis­tics that re­veal an es­ti­mate of less than a penny per year[1].

Effec­tive An­i­mal Ac­tivism, a non-profit eval­u­a­tor for an­i­mal welfare char­i­ties, came up with an es­ti­mate [Ex­cel Doc­u­ment] of $0.04 to $16.60 per year of suffer­ing averted, that also takes into ac­count a va­ri­ety of ad­di­tional vari­ables, like product elas­tic­ity.

Jeff Kauf­man uses a differ­ent line of rea­son­ing, by es­ti­mat­ing how many veg­e­tar­i­ans there are and guess­ing how many of them came via pam­phlets, es­ti­mates it would take $4.29 to $536 to make some­one veg­e­tar­ian for one year. Ex­trap­o­lat­ing from that us­ing at a rate of 255 an­i­mals saved per year and a weighted av­er­age of 329.6 days lived per an­i­mal (see be­low for jus­tifi­ca­tion of both as­sump­tions), would give $0.02 to $1.90 per year of suffer­ing averted[2].

A third line of rea­son­ing, also by Jeff Kauf­man, was to mea­sure the amount of com­ments on the pro-veg­e­tar­ian web­sites ad­ver­tised in these cam­paigns and found that 2-22% of them were about an in­tended be­hav­ior change (eat­ing less meat, go­ing veg­e­tar­ian, or go­ing ve­gan), de­pend­ing on the web­site. I don’t think we can draw any con­clu­sions from this, but it’s in­ter­est­ing.

To make my calcu­la­tions, I de­cided to make a calcu­la­tor. Un­for­tu­nately, I can’t em­bed it here, so you’d have to open it in a new tab as a com­pan­ion piece.

I’m go­ing to start by us­ing the fol­low­ing for­mula: Years of Suffer­ing Averted per Dol­lar = (Pam­phlets /​ dol­lar) * (Con­ver­sions /​ pam­phlet) * (Veg years /​ con­ver­sion) * (An­i­mals saved /​ veg year) * (Days lived /​ an­i­mal)

Now, to get es­ti­ma­tions for these vari­ables.

Pam­phlets Per Dollar

How much does it cost to place the ad­ver­tise­ment, whether it be the pa­per pam­phlet or a Face­book ad­ver­tise­ment? Nick Cooney, head of the Hu­mane League, says the cost-per-click of Face­book ads is 20 cents.

But what about the cost per pam­phlet? This is more of a guess, but I’m go­ing to go with <a href=”″>Ve­gan Outreach’s sug­gested dona­tion of $0.13 per “Com­pas­sion­ate choices” book­let.

How­ever, it’s im­por­tant to note that this cost must also in­clude op­por­tu­nity cost—leafleters must forego the abil­ity to use that time to work a job. This means I must in­clude an op­por­tu­nity cost of say $8/​hr on top of that, mak­ing the ac­tual cost $0.27 as­sum­ing a pam­phlet is given out each minute of vol­un­teer time, mean­ing 3.7 peo­ple are reached per dol­lar from pam­phlets. For Face­book ad­ver­tise­ments, the op­por­tu­nity cost is triv­ial.

Con­ver­sions Per Pamphlet

This is the es­ti­mate with the biggest tar­get on it’s head, so to speak. How many peo­ple do we get to ac­tu­ally change their be­hav­ior with a sim­ple pam­phlet or Face­book ad­ver­tise­ment? Right now, we have three lines of ev­i­dence:

Face­book Study

Hu­mane League did A $5000 Face­book ad­ver­tise­ment cam­paign. They bought ads that look like this...

...and sent peo­ple to web­sites (like this one or this one) with auto-play­ing videos that start play­ing and show the hor­rors of fac­tory farm­ing.

After­ward, there was an­other ad­ver­tise­ment run to peo­ple who “liked” the video page, offer­ing a 1 in 10 chance of win­ning a free movie ticket in or­der to take a sur­vey. Every­one who emailed in ask­ing for a free veg­e­tar­ian starter kit were also emailed a sur­vey. 104 peo­ple took the sur­vey and there were 32 re­ported veg­e­tar­i­ans[3] and 45 peo­ple re­ported, for ex­am­ple, that their chicken con­sump­tion de­creased “slightly” or “sig­nifi­cantly”.

7% of vis­i­tors liked the page and 1.5% of vis­i­tors or­dered a starter kit. As­sum­ing all the other peo­ple went away from the video not chang­ing their con­sump­tion, this sur­vey would lead us to (very ten­u­ously) think about 2.6% of peo­ple see­ing the video will be­come a veg­e­tar­ian[4].

(Here’s the re­sults of the sur­vey in PDF.)

Pam­phlet Study

A sec­ond study dis­cussed in “The Pow­er­ful Im­pact of Col­lege Leaflet­ing (Part 1)” and “The Pow­er­ful Im­pact of Col­lege Leaflet­ing: Ad­di­tional Find­ings and De­tails (Part 2)” looked speci­fi­cally at pam­phlets.

Here, Hu­mane League staff vis­ited two large East Coast state schools and dis­tributed leaflets. They then re­turned two months later and sur­veyed peo­ple walk­ing by. Those who re­mem­ber re­ceiv­ing a leaflet ear­lier were counted. They found about 2% of those re­ceiv­ing a pam­phlet went veg­e­tar­ian.

Vege­tar­ian Years Per Conversion

But once a pam­phlet or Face­book ad­ver­tise­ment cap­tures some­one, how long will they stay veg­e­tar­ian? One sur­vey showed veg­e­tar­i­ans re­frain from eat­ing meat for an av­er­age of 6 years or more. Another study I found says 93% of veg­e­tar­i­ans stay veg­e­tar­ian for at least three years.

An­i­mals Saved Per Vege­tar­ian Year

And once you have a veg­e­tar­ian, how many an­i­mals do they save per year? Count­ingAn­i­mals says 406 an­i­mals saved per year.

The Hu­mane League sug­gests 28 chick­ens, 2 egg in­dus­try hens, 18 beef cow, 12 pig, 1 turkey, and 130 dairy cow per year (to­tal = 31.66 an­i­mals), and does not provide statis­tics on fish. This agrees with Count­ingAn­i­mals on non-fish to­tals.

Days Lived Per Animal

One prob­lem, how­ever, is that sav­ing a cow that could suffer for years is differ­ent from sav­ing a chicken that suffers for only about a month. Us­ing data from Farm Sanc­tu­ary plus World So­ciety for the Pro­tec­tion of An­i­mals data on fish [PDF], I get this table:

An­i­mal Num­ber Days Alive
Chicken (Meat) 28 42
Chicken (Egg) 2 365
Cow (Beef) 0.125 365
Cow (Milk) 0.033 1460
Fish 225 365

This makes the weighted av­er­age 329.6 days[5].

Ac­count­ing For Biases

As I said be­fore, our for­mula was Years of Suffer­ing Averted = (Pam­phlets /​ dol­lar) * (Con­ver­sions /​ pam­phlet) * (Veg years /​ con­ver­sion) * (An­i­mals saved /​ veg year) * (Days lived /​ an­i­mal).

Let’s plug these val­ues in… Years of Suffer­ing Averted per Dol­lar = 5 * 0.02 * 3 * 255.16 * 329.6/​365 = 69.12.

Or, as­sum­ing all this is right (and that’s a big as­sump­tion), it would cost less than 2 cents to pre­vent a year of suffer­ing on a fac­tory farm by buy­ing veg­e­tar­i­ans.

I don’t want to make it sound like I’m be­holden to this cost es­ti­mate or that this es­ti­mate is the “end all, be all” of ve­gan out­reach. In­deed, I share many of the skep­ti­cisms that have been ex­pressed by oth­ers. The sim­ple calcu­la­tion is… well… sim­ple, and it needs some “beefing up”, no pun in­tended. There­fore, I also built a “com­plex calcu­la­tor” that works on a much more com­plex for­mula[6] that is hope­fully cor­rect[7] and will provide a more ac­cu­rate es­ti­ma­tion.

The big, big deal for the sur­veys is con­cern for bias. The most fre­quently men­tioned bias is so­cial de­sir­a­bil­ity bias, or peo­ple who say they re­duced meat just be­cause they want to please the sur­veyor or look like a good per­son, which ac­tu­ally hap­pens a lot more on sur­veys than we’d like.

To ac­count for this, we’ll have to figure out how in­flated an­swers are be­cause of this bias and then scale the an­swers down by that amount. Nick Cooney who says that he’s been read­ing stud­ies that about 25% to 50% of peo­ple who say they are veg­e­tar­ian ac­tu­ally are, though I don’t yet have the cita­tions. Thus, if we find out that an ad­ver­tise­ment cre­ates two meat re­duc­ers, we’d scale that down to one re­ducer if we’re ex­pect­ing a 50% de­sir­a­bil­ity bias.

The sec­ond bias that will be a prob­lem for us is non-re­sponse bias, as those who don’t re­duce their diet are less likely to take the sur­vey and there­fore less likely to be counted. This is es­pe­cially true in the Face­book study, which only mea­sures peo­ple who “liked” or re­quested a starter kit, show­ing some pro-veg­e­tar­ian af­fili­a­tion.

We can bal­ance this out by as­sum­ing ev­ery­one who didn’t take the sur­vey went on to have no be­hav­ior change what­so­ever. Nick Cooney’s Face­book Ad Sur­vey is for the 7% of peo­ple who liked the page (and then re­sponded to the sur­vey), and ob­vi­ously those who liked the page are more likely to re­duce their con­sump­tion. I chose an op­ti­mistic value of 90% to con­sider the sur­vey com­pletely rep­re­sen­ta­tive of the 7% who liked the page, and then a bit more for those who re­duced their con­sump­tion but did not like the page. My pes­simistic value was 95%, as­sum­ing ev­ery­one who did not like the sur­vey went un­changed and as­sum­ing a small re­sponse bias among those who liked the page but chose not to take the sur­vey.

For the pam­phlets, how­ever, there should be no re­sponse bias since the en­tire pop­u­la­tion of col­lege stu­dents was sur­veyed from ran­domly, and no one was said to re­ject tak­ing the sur­vey.

Ad­di­tional Peo­ple Are Be­ing Reached

In the Face­book sur­vey, those who said they re­duced their meat con­sump­tion were also asked if they in­fluenced any of their friends and fam­ily to also re­duce eat­ing meat, and found that they usu­ally pro­duced 0.86 ad­di­tional re­duc­ers.

This figure seems very high, but I do strongly ex­pect the figure to be pos­i­tive—peo­ple who re­duce eat­ing meat will talk about it some­times, es­sen­tially be­com­ing free ad­ver­tise­ments. I’d be very sur­prised if they ended up be­ing a net nega­tive.

Ac­count­ing for Product Elasticity

Another way to boost the effec­tive­ness of the es­ti­mate is to be more ac­cu­rate about what hap­pens when some­one stops eat­ing meat. The change isn’t from the ac­tual re­fusal to eat, but rather from the re­duced de­mand for meat, which leads to a re­duced sup­ply. Fol­low­ing the laws of eco­nomics, how­ever, this re­duc­tion won’t nec­es­sar­i­ally be one-for-one, but rather de­pend on the elas­tic­ity of product de­mand and sup­ply. By get­ting this num­ber, we can find out how much meat is re­duced for ev­ery meat not de­manded.

My guesses in the calcu­la­tor come from the fol­low­ing sources, some of which are PDFs: Beef #1, Beef #2, Dairy #1, Dairy #2, Pork #1, Pork #2, Egg #1, Egg #2, Poul­try, Sal­mon, and for all fish.

Put­ting It All Together

Im­ple­ment­ing the for­mula on the calcu­la­tor, we end up with an es­ti­mate of $0.03 to $36.52 to re­duce one year of suffer­ing on a fac­tory farm based on the Face­book ad data and an es­ti­mate of $0.02 to $65.92 based on the pam­phlet data.

Of course, many peo­ple are skep­ti­cal of these figures. Per­haps sur­pris­ingly, so am I. I’m try­ing to strike a bal­ance be­tween be­ing an ad­vo­cate of ve­gan out­reach as a very promis­ing path for mak­ing the world a bet­ter place, while not los­ing sight of the method­olog­i­cal hur­dles that have not yet been met, and open to the pos­si­bil­ity that I’m wrong about this.

The big method­olog­i­cal elephant in the room is that my en­tire cost es­ti­mate de­pends on hav­ing a plau­si­ble guess for how likely some­one is to change their be­hav­ior based on see­ing an ad­ver­tise­ment.

I feel slightly re­as­sured be­cause:

  1. There are two sur­veys for two differ­ent me­dia, and they both provide es­ti­mates of im­pact that agree with each other.

  2. Th­ese es­ti­mates also match anec­dotes from leafleters about ap­prox­i­mately how many peo­ple come back and say they went veg­e­tar­ian be­cause of a pam­phlet.

  3. Even if we were to take the sim­ple calcu­la­tor and drop the “2% chance of get­ting four years of veg­e­tar­i­anism” as­sump­tion down to, say, a pes­simistic “0.1% chance of get­ting one year” con­ver­sion rate, the es­ti­mate is still not too bad -- $0.91 to avert a year of suffer­ing.

  4. More stud­ies are on the way. Nick Cooney is go­ing to do a bunch more to study leaflets, and Xio Kikauka and Joey Savoie have pub­li­cly pub­lished some sur­vey method­ol­ogy [Google Docs].

That said, the pos­si­bil­ity for de­sir­a­bil­ity bias in the sur­vey is a large con­cern as long as the sur­veys con­tinue to be from overt an­i­mal welfare groups and con­tinue to clearly state that they’re look­ing for re­duc­tions in meat con­sump­tion.

Also, so long as sur­veys are only given to peo­ple that re­mem­ber the leaflet or ad­ver­tise­ment, there will be a strong pos­si­bil­ity of re­sponse bias, as those who re­mem­ber the ad are more likely to be the ones who changed their be­hav­ior. We can at­tempt to com­pen­sate for these things, but we can only do so much.

Fur­ther­more, and more wor­ry­ing, there’s a con­cern that the sur­veys are just mea­sur­ing nor­mal drift in veg­e­tar­i­anism, with­out any changes be­ing at­tributable to the ads them­selves. For ex­am­ple, imag­ine that ev­ery year, 2% of peo­ple be­come veg­e­tar­i­ans and 2% quit. Sur­vey­ing these peo­ple at ran­dom and not cap­tur­ing those who quit will end up find­ing a 2% con­ver­sion rate.

How can we ad­dress these? I think all three prob­lems can be solved with a de­cent con­trol group, whether it be a group of peo­ple that re­ceive a leaflet not about veg­e­tar­i­anism, or no leaflet at all. Luck­ily, Kikauka and Savoie’s sur­vey in­tend to do just that.

Jeff Kauf­man has a good pro­posal for a sur­vey de­sign I’d like to see im­ple­mented in this area.

Mar­ket Sat­u­ra­tion and Diminish­ing Marginal Re­turns?

Another con­cern is that there are diminish­ing marginal re­turns to these ads. As the cri­tique goes, there are only so many peo­ple that will be eas­ily swayed by the ad­ver­tise­ment, and once all of them are quickly reached by Face­book ads and pam­phlets, things will dry up.

Un­like the oth­ers, I don’t think this crit­i­cism works well. After all, even if it were true, it still would be worth­while to take the mar­ket as far as it will go, and we can keep mon­i­tor­ing for sat­u­ra­tion and find the point where it’s no longer cost-effec­tive.

How­ever, I don’t think the mar­ket has been tapped up yet at all. Ac­cord­ing to Nick Cooney [PDF], there are still many op­por­tu­ni­ties in for­eign mar­kets and out­side the young, col­lege kid de­mo­graphic.

The Con­junc­tion Fal­lacy?

The con­junc­tion fal­lacy is a clas­sic fal­lacy that re­minds us that no mat­ter what, the chance of event A hap­pen­ing can never be smaller than the chance of event A hap­pen­ing, fol­lowed by event B. For ex­am­ple, the prob­a­bil­ity that Linda is a bank tel­ler will always be larger than (or equal to) the prob­a­bil­ity that Linda is a bank tel­ler and a fem­i­nist.

What does this mean for veg­e­tar­ian out­reach? Well, for the sim­ple calcu­la­tor, we’re es­ti­mat­ing five fac­tors. In the com­plex calcu­la­tor, we’re es­ti­mat­ing 90 fac­tors. Even if each fac­tor is 99% likely to be cor­rect, the chance that all five are right is 95%, and the chance that all 50 are right is only 60%. If each fac­tor is only 90% likely to be cor­rect, the com­plex calcu­la­tor will be right with a prob­a­bil­ity of 0.5%!

This is a cause for con­cern, but I don’t think there’s any way around this. It’s just an in­her­ent prob­lem with es­ti­ma­tion. Hope­fully we’ll be bal­anced by (1) us­ing the differ­ent bounds and (2) hop­ing un­der­es­ti­mates and over­es­ti­mates will can­cel each other out.

Con­ver­sion and The 100 Yard Line

Some­thing we should take into ac­count that helps the case for this out­reach rather than hurts it is the idea that con­ver­sions aren’t bi­nary—some­one can be pushed by the ad to be more likely to re­duce their meat in­take as op­posed to fully con­verted. As Brian To­masik puts it:

Yes, some of the peo­ple we con­vince were already on the bor­der, but there might be lots of other peo­ple who get pushed fur­ther along and don’t get all the way to veg­ism by our in­fluence. If we pic­ture the path to veg­ism as a 100-yard line, then maybe we push ev­ery­one along by 20 yards. 15 of peo­ple cross the line, and this is what we see, but the other 45 get pushed closer too. (Ob­vi­ously an overly sim­plis­tic model, but it illus­trates the idea.)

This would be ei­ther very difficult or out­right im­pos­si­ble to cap­ture in a sur­vey, but is some­thing to take into ac­count.

Three Places I Might Donate Be­fore Donat­ing to Ve­gan Outreach

When all is said and done, I like the case for fund­ing this out­reach. How­ever, I think there are three other pos­si­bil­ities along these lines that I find more promis­ing:

Fund­ing the re­search of ve­gan out­reach: There needs to be more and higher-qual­ity stud­ies of this be­fore one can feel con­fi­dent enough in the cost-effec­tive­ness of this out­reach. How­ever, ini­tial re­sults are very promis­ing, and the value of in­for­ma­tion of more stud­ies is there­fore very high. Stud­ies can also find ways to ad­ver­tise more effec­tively, in­creas­ing the im­pact of each dol­lar spent. Right now, how­ever, it looks like all on­go­ing stud­ies are fully funded, but if there were op­por­tu­ni­ties to fund more, I would jump on it.

Fund­ing Effec­tive An­i­mal Ac­tivism: EAA is an or­ga­ni­za­tion push­ing for more cost-effec­tive­ness in the do­main of non­hu­man an­i­mal welfare and is work­ing to fur­ther eval­u­ate what op­por­tu­ni­ties are the best, Givewell-style. Giv­ing them more money can po­ten­tially at­tract a lot more at­ten­tion to this out­reach, and get it more scrutiny, re­search, and money down the line.

Fund­ing Cen­tre for Effec­tive Altru­ism: Over­all, it might just be bet­ter to get more peo­ple in­volved in the idea of giv­ing effec­tively, and then get­ting them in­ter­ested in ve­gan out­reach, among other things.


Ve­gan out­reach is a promis­ing, though not fully stud­ied, method of out­reach that de­serves both ex­cite­ment and skep­ti­cism. Should one put money into it? Over­all, I’d take a guarded ap­proach of putting in just enough money to help the or­ga­ni­za­tions learn, de­velop bet­ter cost-effec­tive mea­sure­ments and trans­parency, and be­come more effec­tive. It shouldn’t be too long be­fore this area will be­come stud­ied well enough to have good con­fi­dence in how things are do­ing.

More stud­ies should be de­vel­oped that ex­plore ad­ver­tis­ing veg­e­tar­i­anism in a wide va­ri­ety of me­dia in a wide va­ri­ety of ways, with de­cent con­trol groups.

I look for­ward to see­ing how this de­vel­ops. Don’t for­get to play around with my calcu­la­tor.



[1]: Cost effec­tive­ness in years of suffer­ing pre­vented per dol­lar = (Pam­phlets /​ dol­lar) * (Con­ver­sions /​ pam­phlet) * (Veg years /​ con­ver­sion) * (An­i­mals saved /​ veg year) * (Years lived /​ an­i­mal).

Plug­ging in 80K’s val­ues… Cost effec­tive­ness = (Pam­phlets /​ dol­lar) * 0.01 to 0.03 * 25 * 100 * (Years lived /​ an­i­mal)

Filling in the gaps with my best guesses… Cost effec­tive­ness = 5 * 0.01 to 0.03 * 25 * 100 * 0.90 = 112.5 to 337.5 years of suffer­ing averted per dol­lar
I per­son­ally think 25 veg-years per con­ver­sion on av­er­age is pos­si­ble but too high; I per­son­ally err from 4 to 7.
[2]: I feel like there’s an er­ror in this calcu­la­tion or that Kauf­man might dis­agree with my as­sump­tions of num­ber of an­i­mals or days per an­i­mal, be­cause I’ve been told be­fore that these es­ti­mates with this method are sup­posed to be about an or­der of mag­ni­tude higher than other es­ti­mates. How­ever, I emailed Kauf­man and he seemed to not find any fault with the calcu­la­tion, though he does think the method­ol­ogy is bad and the calcu­la­tion should not be taken at face value.
[3]: I calcu­lated the num­ber of veg­e­tar­i­ans by eye­bal­ling about how many peo­ple said they no longer eat fish, which I’d guess only a veg­e­tar­ian would be will­ing to give up.
[4]: 32 veg­e­tar­i­ans /​ 104 peo­ple = 30.7%. That pop­u­la­tion is 8.5% (7% for likes + 1.5% for the starter kit) of the over­all pop­u­la­tion, lead­ing to 2.61% (30.7% * 8.5%).
[5]: For­mula is [(Num­ber Meat Chick­ens)(Days Alive) + (Num­ber Egg Chick­ens)(Days Alive) + (Num­ber Beef Cows)(Days Alive) + (Num­ber Milk Cows)(Days Alive) + (Num­ber Fish)(Days Alive)] /​ (To­tal Num­ber An­i­mals). …Plug­ging things in: [(28)(42) + (2)(365) + (0.125)(365) + (0.033)(1460) + (225)(365)] /​ 255.16] = 329.6 days

Cost effec­tive­ness in amount of days pre­vented per dol­lar = (Peo­ple Reached /​ Dol­lar + (Peo­ple Reached /​ Dol­lar * Ad­di­tional Peo­ple Reached /​ Direct Reach * Re­sponse Bias * De­sir­a­bil­ity Bias)) * Years Spent Re­duc­ing * (((Per­cent In­creas­ing Beef * In­crease Value) + (Per­cent Stay­ing Same with Beef * Stay­ing Same Value) + (Per­cent De­creas­ing Beef Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Beef Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Beef * Elimi­na­tion Value) + (Per­cent Never Ate Beef * Never Ate Value)) * Nor­mal Beef Con­sump­tion * Beef Elas­tic­ity * (Aver­age Beef Lifes­pan + Days of Suffer­ing from Beef Slaugh­ter)) + (((Per­cent In­creas­ing Dairy * In­crease Value) + (Per­cent Stay­ing Same with Dairy * Stay­ing Same Value) + (Per­cent De­creas­ing Dairy Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Dairy Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Dairy * Elimi­na­tion Value) + (Per­cent Never Ate Dairy * Never Ate Value)) * Nor­mal Dairy Con­sump­tion * Dairy Elas­tic­ity * (Aver­age Dairy Lifes­pan + Days of Suffer­ing from Dairy Slaugh­ter)) + (((Per­cent In­creas­ing Pig * In­crease Value) + (Per­cent Stay­ing Same with Pig * Stay­ing Same Value) + (Per­cent De­creas­ing Pig Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Pig Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Pig * Elimi­na­tion Value) + (Per­cent Never Ate Pig * Never Ate Value)) * Nor­mal Pig Con­sump­tion * Pig Elas­tic­ity * (Aver­age Pig Lifes­pan + Days of Suffer­ing from Pig Slaugh­ter)) + (((Per­cent In­creas­ing Broiler Chicken * In­crease Value) + (Per­cent Stay­ing Same with Broiler Chicken * Stay­ing Same Value) + (Per­cent De­creas­ing Broiler Chicken Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Broiler Chicken Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Broiler Chicken * Elimi­na­tion Value) + (Per­cent Never Ate Broiler Chicken * Never Ate Value)) * Nor­mal Broiler Chicken Con­sump­tion * Broiler Chicken Elas­tic­ity * (Aver­age Broiler Chicken Lifes­pan + Days of Suffer­ing from Broiler Chicken Slaugh­ter)) + (((Per­cent In­creas­ing Egg * In­crease Value) + (Per­cent Stay­ing Same with Egg * Stay­ing Same Value) + (Per­cent De­creas­ing Egg Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Egg Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Egg * Elimi­na­tion Value) + (Per­cent Never Ate Egg * Never Ate Value)) * Nor­mal Egg Con­sump­tion * Egg Elas­tic­ity * (Aver­age Egg Lifes­pan + Days of Suffer­ing from Egg Slaugh­ter)) + (((Per­cent In­creas­ing Turkey * In­crease Value) + (Per­cent Stay­ing Same with Turkey * Stay­ing Same Value) + (Per­cent De­creas­ing Turkey Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Turkey Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Turkey * Elimi­na­tion Value) + (Per­cent Never Ate Turkey * Never Ate Value)) * Nor­mal Turkey Con­sump­tion * Turkey Elas­tic­ity * (Aver­age Turkey Lifes­pan + Days of Suffer­ing from Turkey Slaugh­ter)) + (((Per­cent In­creas­ing Farmed Fish * In­crease Value) + (Per­cent Stay­ing Same with Farmed Fish * Stay­ing Same Value) + (Per­cent De­creas­ing Farmed Fish Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Farmed Fish Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Farmed Fish * Elimi­na­tion Value) + (Per­cent Never Ate Farmed Fish * Never Ate Value)) * Nor­mal Farmed Fish Con­sump­tion * Farmed Fish Elas­tic­ity * (Aver­age Farmed Fish Lifes­pan + Days of Suffer­ing from Farmed Fish Slaugh­ter)) + (((Per­cent In­creas­ing Sea Fish * In­crease Value) + (Per­cent Stay­ing Same with Sea Fish * Stay­ing Same Value) + (Per­cent De­creas­ing Sea Fish Slightly * De­crease Slightly Value) + (Per­cent De­creas­ing Sea Fish Sig­nifi­cantly * De­crease Sig­nifi­cantly Value) + (Per­cent Elimi­nat­ing Sea Fish * Elimi­na­tion Value) + (Per­cent Never Ate Sea Fish * Never Ate Value)) * Nor­mal Sea Fish Con­sump­tion * Sea Fish Elas­tic­ity * Days of Suffer­ing from Sea Fish Slaugh­ter) * Re­sponse Bias * De­sir­a­bil­ity Bias
[7]: Feel free to check the for­mula for ac­cu­racy and also check to make sure the calcu­la­tor im­ple­ments the for­mula cor­rectly. I worry that the added ac­cu­racy from the com­plex calcu­la­tor is out­weighed by the risk that the for­mula is wrong.


Edited 18 June to cor­rect two ty­pos and up­date foot­note #2.

Also cross-posted on my blog.