Thanks for sharing, Keyvan! Strongly upvoted.

With the French branch of Anima International, we also made similar estimates to evaluate our work with school and university canteens in France. We plan to make a post about this analysis.

Nice that you plan to publish your results.

even if we advocated mainly for plant-based meals in France, often our partners implemented vegetarian meals, which often contained eggs. Since egg meals (particularly coming from caged hens) cause a lot of suffering (approximately as much as in chicken meals), it signifcantly lowered our effectiveness. So it would be worth checking in your analysis that the meals were shifted to 100% plant-based ones

Right. I assumed all additional meat-free meals to be plant-based for simplicity (as I noted in the post), but the potential presence of eggs means I have overestimated the cost-effectiveness of School Plates. I have just asked Sarah whether she know the fraction of meat-free meals which are plant-based. For now I have updated the analysis assuming a fraction of 2/3.

Thanks for the great points, Blake, and welcome to the EA Forum!

On 1, to clarify, my understanding is that Sarah expects "additional meat-free meals in 2023"/"cost in 2023" to be lower than "additional meat-free meals in 2024"/"cost in 2024", i.e. she expects the ratio between annual benefits and cost to increase. Despite of this, for any year, I expect that "annual additional meat-free meals"/"annual cost" > "additional meat-free meals from spending an extra e.g. 1 k$ in a given year"/"e.g. 1k$" = "marginal cost-effectiveness". Do you agree? For any given year, I expect School Plates to start spending on the most cost-effective activities 1st, such that the benefits produced by the last dollar spent in any given year are smaller than those produced by the mean dollar that same year.

On 2, at least in principle, I fully endorse expected total hedonistic utilitarianism, which only accounts for wellbeing. However, in practice, I would agree it can still make perfect sense to account for metrics which do not have to do with wellbeing per se. They could inform one about longer term impacts on wellbeing, or be an indicator about near term impacts on wellbeing which are not being captured by the wellbeing metrics for some reason. It is unclear to me whether accounting for other metrics from this perspective would favour School Plates, as corporate campaigns might also generate momentum for further welfare campaigns, and eventually accelerate the phase-out of factory-farming (or the transition to a net positive factory-farming).

I'm thinking of potentially building out some Monte Carlo Simulations of your model and Saulius' model (with Open Phil's comments) to see how accounting for variance impacts these estimates (my hunch is there will be so much uncertainty it will be hard to decide between the interventions).

I do not think the Monte Carlo would change the mainline cost-effectiveness estimates much:

• The inputs I used are supposed to be means rather than medians or modes. So, if one modelled the distributions such as their means correspond to my point estimates, the cost-effectiveness would be maintained if it was a sum of products, because e.g. E(X1*X2 + X3*X4) = E(X1) E(X2) + E(X3) E(X4) assuming all distributions are independent (as I would if I was to run a Monte Carlo).
  • In reality, my estimate of the cost-effectiveness involves 2 variables in the denominator, the cost of the program in 2023 and the number of lunches and dinners per person per year, but these are arguably 2 of the most certain variables. So approximating E(1/X) as 1/E(X), as I implicitly did, should be fine. If I wanted to be more rigorous, I could also calculate the mean of the reciprocal of the variables in the denominator from 2 percentiles using the formulas here, thus not having to run the whole Monte Carlo.
• A large overlap between the cost-effectiveness distributions of 2 interventions does not necessarily imply uncertainty about which intervention is best if the Monte Carlo assumes all variables are independent. This is because there may be correlations across variables used to calculate the cost-effectiveness of both interventions.
  • In particular, the welfare range of chickens, and welfare of chickens per time as a fraction of their welfare range are 2 of the most uncertain variables, and will be same for corporate campaigns and School Plates.
  • Here is an extreme example illustrating the issue I am pointing to:
    • Intervention A has a cost-effectiveness given by X1*Y, where X1 is a super uncertain distribution spanning many orders of magnitude, and Y is practically a point estimate of 1.
    • Intervention B has a cost-effectiveness given by X2*Z, where X2 is distributed as X1, and Z is practically a point estimate of 1.1.
    • Running a Monte Carlo with all the distributions as independent would result in almost perfect overlap between the cost-effectiveness distributions of A and B. So one may be tempted to conclude it is unclear which interventions is best.
    • However, if X1 and X2 are perfectly correlated, the correct conclusion is that B is almost certainly better than A (1.1 > 1).
  • In any case, the issue could be solved by setting all uncertain distributions shared across interventions to their means. I guess modelling the correlations within the Monte Carlo would be significantly more work for little benefit.

Before running a Monte Carlo with some guesses for the distributions of each variable, I think it would be good to get more information about the variables with the most reducible uncertainty. Yet, the conclusion that corporate campaigns are more cost-effective is pretty robust:

• Corporate campaigns are more cost-effective even for most favourable compositions of baseline meals. Playing around with the Sheet:
  • Assuming all the meat in the baseline meals is poultry, and the meat-free meals are all plant-based^[1], corporate campaigns are still 70.3 times as cost-effective as School Plates.
    • It makes sense the ratio is smaller than that of 186 I estimated.
    • Poultry is the meat with the highest suffering-adjusted animal living time (animal living live times welfare range) per mass, equal to 9.53 year/kg (= 28.7*0.332).
  • Assuming all the meat in the baseline meals is farmed fish and seafood, and the meat-free meals are all plant-based^[2], corporate campaigns are still 89.4 times as cost-effective as School Plates.
    • It makes sense the ratio is smaller than that of 186 I estimated, but higher than that of 70.3 I got just above.
    • Farmed fish and seafood is the meat with 2nd highest suffering-adjusted animal living time per mass, equal to 7.31 year/kg (= 82.1*0.089).
    • Reality check. The meat in the baseline meals being poultry is 1.27 (= 89.4/70.3) times as cost-effective as it being farmed fish and seafood, which is quite close to the ratio of 1.30 (= 9.53/7.31) suggested by the suffering-adjusted animal living time per mass. The values do not have to be exactly the same due to the presence of eggs in the baseline meals.
• Supposing lunches and dinners account for 100 % of the animal living time instead of 75 % only makes the cost-effectiveness of School Plates 1.33 (= 1/0.75) times as high, so corporate campaigns would still be 140 (= 186/1.33) times as cost-effective.
• Assuming all the meat in the baseline meals is poultry, that lunches and dinners account for 100 % of the animal living time instead of 75 %, and very optimistically that the marginal cost-effectiveness of School Plates is equal to the ratio in 2023 between benefits and cost, corporate campaigns would still be 26.4 (= 70.3/1.33*0.5) times as cost-effective as School Plates.
• In general, this cost-effectiveness analysis is quite linear, and I am not envisionaing any plausible combination of factors which would make the cost-effectiveness of School Plates increasing by a factor of 186.

I hope this isn't coming off as overly critical.

I strongly upvoted your comment, as it made me think a little bit more about relevant questions. Sorry if I sound overly critical above too!

1. ^{^}

   This can be defined in the Sheet by assuming here a consumption of poultry of 82.3 kg/person/year (meat consumption per capita in the UK in 2021), and no consumption of other meats, hard coding eggs' suffering-adjusted animal living time per annual food consumption to my original value of 0.198 year/person (in the original sheet, it is defined from the value for poultry), and making the cost per meal swapped to meat-free 2/3 as high as my original value (since I assumed only 2/3 of meat-free meals are plant-based, and meat-free non-plant-based meals to be as bad as the conventional ones).

2. ^{^}

   This can be defined in the Sheet by assuming here a consumption of farmed fish and seafood of 123 kg/person/year, and no consumption of other meats, hard coding eggs' suffering-adjusted animal living time per annual food consumption to my original value of 0.198 year/person, and making the cost per meal swapped to meat-free 2/3 as high as my original value (see previous footnote for details).

Thanks for the comment, Joseph!

Will this food be healthier?

I think so. According to the EAT-Lancet Commision, the global adoption of a predominantly plant-based healthy diet, with just 13.6 % (= (153 + 15 + 15 + 62 + 19 + 40 + 36)/2500; see Table 1) of calories coming from animals, would decrease premature deaths of adults by 21.7 % (= (0.19 + 0.224 + 0.236)/3; mean of the 3 estimates in Table 3). However, I assume this requires longterm dietary change, and I do not know whether School Plates leads to that, so I have not accounted for potential health benefits to humans. Likewise, I have neglected potential health benefits coming from corporate campaigns making chicken and eggs slightly more expensive.

Will they like the food?

I determined a suffering-adjusted animal living time per meal in the UK of 0.500 d, i.e. 12.0 h (= 0.500*24). The harms from this seem much larger than the potential increase/decrease in hapiness due to eating a meat-free or plant-based meal.

Thanks, Mathias!

Do you have a spreadsheet with the calculations?

I did not, but I have just created one since you asked. I arrived to the same results (I could have arrived to different ones if I had had errors in the manual calculations). I have not included the sources of the inputs, but you can check them in the post.