[Thanks to Pablo S. for suggesting that I cross-post this here.]

A year ago, Scott Alexander argued that it’s better to eat beef than chicken, on the (interesting but questionably relevant) grounds that it’s vastly cheaper to offset the climate costs of beef than the animal welfare costs of chicken:

Eating beef causes more climate change than eating chicken, but eating chicken causes more animal suffering than eating beef. Offsetting the climate change effects of beef would only cost $22 per year, which seems really good. Offsetting the animal suffering effects of chicken might only cost $360 per year, but this is a very tentative estimate and maybe shouldn't be taken seriously. Also, these only work if you're actually doing the offsetting. If not, you should probably default to eating beef over chicken, but I can't prove it.

So I was excited to hear Kevin Kuruc’s talk on ‘Monetizing the Externalities of Animal Agriculture’ (you can find the full paper on his website), extending standard economic models of the “social cost of carbon” to additionally estimate the “social cost” of factory-farmed animal suffering. The headline result:

We find that the welfare costs of global animal agriculture are very large in the case that animals do not have net-pleasurable existences: the monetized costs of producing the meat consumed for the Standard American Diet (SAD) for one person is on the order of $100,000 per year under our baseline parameters. In other words, eliminating the production of meat required for one individual’s diet for one year confers social welfare benefits equal to the benefits of increasing annual global output by more than $100,000.

While this particular number is highly sensitive to the baseline parameters of the model, the broader conclusion that animal welfare costs completely swamp the climate costs of eating meat turns out to be almost unavoidable once you grant that factory-farmed animal lives are net-negative.

Note that, while the animal welfare costs of the Standard American Diet are on the order of $100,000 per year, the climate costs are a mere $47. Combining these with Scott Alexander’s estimates of offsetting efficacy yields some interesting results. Suppose for simplicity that the SAD involves equal parts beef and chicken. (This is presumably incorrect, so take the following numbers with a large grain of salt.) $47 worth of climate costs could then be prevented with a mere $11 to effective climate charities. (Good value!) Whereas >$100,000 worth of animal suffering costs could be prevented with ~$180 donated to effective animal suffering charities. (Insanely good value!)

I should re-emphasize that these numbers are unreliable. But they indicate at least some back-of-the-envelope reason to expect effective animal charities to do (vastly!) more good per $ than climate charities. And even when replacing all chicken with beef, the welfare costs still dwarf the climate costs by many orders of magnitude. So for reasons of both efficacy and reparative justice, it seems that meat eaters should eat (only) beef and then prioritize further offsetting the animal welfare costs of being non-vegetarian, rather than merely offsetting the (comparatively trivial) climate costs.

So that’s an interesting result. One thing I’d be curious to hear more about is how the ~$100,000 in negative externalities compares to the (i) intrinsic value, and (ii) positive externalities of a Standard American year of life. IIRC, the value of a statistical life-year in the US is itself on the order of $100,000. So the harm of a Standard American Diet roughly balances out the intrinsic value of a standard American life (on standard economic approaches). If you’re neither vegetarian nor offsetting, here’s hoping that you produce enough positive externalities to get your life (overall) back into the green!

Please add a comment if you know of any good work on the average value of (ii).  Or of how to adjust for effects on wild animals of reducing agricultural footprints. But in any case, I highly recommend Kevin's paper to anyone interested in this topic!