Linkpost: Prospective cost-effectiveness of farmed fish stunning corporate commitments in Europe

By Sagar K Shah, Rethink Priorities @ 2024-03-15T15:06 (+74)

This is a linkpost to https://rethinkpriorities.org/publications/farmed-fish-corporate-commitments

Short summary

Longer summary


Vasco Grilo @ 2024-03-16T21:15 (+11)

Thanks for sharing, Sagar!

Farmed fish slaughter commitments do not look cost-effective using an estimation method that prioritizes duration and does not assign a high moral value to averting intense suffering.

I do think your methodology greatly underestimates the value of averting extreme suffering. You say:

To calculate the direct $/DALY range, I assumed that the stunning intervention leads to a welfare improvement between 10% and 50% of the entire fish welfare range (both positive and negative), that lasts for 50% to 90% of the duration of slaughter without stunning.

[...]

To convert this into DALYs averted, I assumed that an intervention that lasts for a year and generates an average welfare improvement of 50% of the entire human welfare range is equivalent to averting a DALY.

The assumptions in the 1st of the above paragraphs make sense to me if I interpret the welfare range as i) the difference between the welfare per unit time of the best and worst possible experience of 1 second, rather than ii) the difference between the welfare per unit time of the best and worst possible experience of 1 year (this can also be thought of as the difference between the welfare per unit time of the best and worst typical experience). However, for the 2nd paragraph to make sense, one has to interpret the welfare range as ii). So I think there is a contradiction:

Am I missing something?

MHR @ 2024-03-17T15:12 (+13)

I agree with this comment. It's worth nothing that the methodology used in this analysis isn't the same as the methodology used in the CURVE sequence. In the "How Can Risk Aversion Affect Your Cause Prioritization" report, @Laura Duffy weighted 1 year of disabling pain at 2 to 10 DALYs and 1 year of excruciating pain at 60 to 150 DALYs. I expect that dying is at least disablingly painful and potentially excruciatingly painful, so these weights would imply a >5x improvement in cost-effectiveness (but even at the upper end, this probably wouldn't be cost-competitive with top EA interventions). 

In general, I think it's a good step to try and actually put interventions from different cause areas on the same scale, but I continue to think that because DALYs are a unit of health status and not a unit of utility, trying to use them as a unit of comparison is unlikely to be optimal (see here and here for more)

Sagar K Shah @ 2024-03-18T14:10 (+3)

Thank you for your comments, Matt!

I would agree on that this intervention would look better (in $/DALY space) if I were to have adopted the same assumptions as @Laura Duffy and come up with some plausible assumptions how much time in various pain intensities that would be averted through the intervention.  I also think its very unlikely the intervention would look competitive the top AW and GHD interventions.  Under the assumptions where this intervention were to look very competitive, I'd suspect shrimp stunning interventions would look even better.

Thanks also for your very valid comments on using DALYs as a unit to compare interventions (and your general engagement on the research that @Rethink Priorities does!).

Sagar K Shah @ 2024-03-18T13:51 (+3)

Thank @Vasco Grilo  you for your thoughtful comments.  Appreciate it!

I don’t think you’ve missed anything. I think you've identified a very valid critique of the assumptions I used to express cost-effectiveness as a cost per DALY averted range.  Expressing the welfare ranges in units of seconds or years is a great way of bringing this out – so thank you for doing that.

Some comments:

  • If I were to rebuild the cost-effectiveness model, with the benefit of hindsight (and more time), I’d have probably used a probabilistic rather than deterministic variable for the assumption converting the % improvement in the human welfare range (for one year) that is equivalent to averting a DALY.
  • I’m pretty sure assumption feeds through linearly into the $/DALY results.  So if you believed an assumption of 5% of human welfare range was more appropriate than 50%, you could divide the  5th and 95th percentiles of the cost per DALY averted range.
  • The formal sensitivity tests I did suggest the conclusions of how this intervention looks compared to the most promising GHD and animal welfare interventions wouldn’t change with ‘relatively small’ adjustments to the assumptions needed to convert results into DALY space (e.g.  doubling the fish welfare range relative to humans and assuming averting a DALY is equivalent to a human intervention that raises human welfare by 10% of the human welfare range for 1 year).
  • I think once you start making bigger adjustments to these assumptions, you can run into the risk of being criticised for placing too much moral value on short-duration but high intensity suffering.  I don’t think we have good empirical evidence to support any particular assumption here.
  • The moral value section of the results more formally illustrates how the fish stunning intervention compares to various $/DALY benchmarks depending on the moral value you might assign to improving a year of fish life via the intervention relative to averting a DALY.
  • I don’t think the narrative expressed in the executive summary would change even if I were to change the assumption on the moral value of averting intense suffering relative to extending healthy lifespan.
  • While I think there is a lot of value in trying to place results into a ‘common currency’, I think this is also a good reason why cost per DALY averted numbers should always be treated with some caution (there is will always be moral value judgements there, some of which may be objectionable).  I think it’s valuable important to look at a number of different metrics (number of animals affected, amount of time affected) to assess how promising an animal welfare intervention looks.
Vasco Grilo @ 2024-03-16T22:06 (+7)

I estimated the cost-effectiveness of farmed fish slaughter commitments to be between $10.4K and $114M per DALY averted.

Animal welfare is often conceptualised as just one area, but the above illustrates the cost-effectiveness can vary a lot depending on the species and type of intervention. So I think it is great that you are willing to estimate the cost-effectiveness in terms of DALY/$[1].  It makes me more willing to donate to Rethink Priorities instead of Animal Charity Evaluators' (ACE's) recommended charities or the Animal Welfare Fund (AWF), because these are not estimating cost-effectiveness in terms of DALY/$ (or similar). Both ACE and AWF assess cost-effectiveness based on heuristics[2], but I am not confident they are sufficient to figure out which are the best animal welfare interventions. I see GiveWell's cost-effectiveness analyses as quite important to determine the best interventions in global health and development, so I assume having similar analyses in the context of animal welfare is quite useful too.

To put these numbers in context, $50 per DALY averted [or 0.02 DALY/$ (= 1/50)] is considered a proxy for some of the most promising human global health and development interventions. The best animal interventions are often considered to be even more competitive than this.

For reference, I guess the cost-effectiveness of corporate campaigns for chicken welfare is 13.6 DALY/$ (= 0.01*1.37*10^3), i.e. 680 (= 13.6/0.02) times Open Philanthropy's bar. I got that multiplying:

  1. ^

    Although I think you are underestimating the cost-effectiveness.

  2. ^

    In addition, from Giving What We Can's evaluation of AWF:

    Fourth, we saw some references to the numbers of animals that could be affected if an intervention went well, but we didn’t see any attempt at back-of-the-envelope calculations to get a rough sense of the cost-effectiveness of a grant, nor any direct comparison across grants to calibrate scoring.