Thanks! Appreciate your thoughtful reply, especially on mackerel/herring.

I don't think stress duration itself changes the overall conclusions of this work, especially as my best guess is that increasing human (food) demand for sardines/anchovies might not counterfactually increase catch volumes for these species (unless it increases political pressure for increased quotas).  

That said, I remain pretty uncertain about what the consequences of pushing up demand for these species might be.  On the one hand, it could push up prices for fishmeal, which in turn could raise input prices for aquaculture for carnivorous/omnivious species.  But on the other hand, it could also push up prices for sardines/anchovies, which in turn could push omnivores/pesceterians who currently eat sardines/anchovies to eat other foods.  Those second-round effects seem pretty hard to know with confidence, but seems pretty plausible those folks could switch from anchovies/sardines to farmed salmon/shrimp or land-based meats like chicken.

 

Thanks for a very thought provoking post.  

I'd tend to agree that wild-caught small forage-feeding pelagic fish like anchovies/sardines might be among the animal products that humans could consume with the lowest counterfactual harm and the greatest nutritional benefit to people on otherwise largely plant-based diets.

From an animal advocacy perspective, I think its useful to have specific suggestions on what to eat for people who are resistant to going vegan or would find it very hard to eliminate all animal products, and this post has prompted me to consider small pelagic fish more seriously.

A small nitpick is that I believe the duration of stress experienced by small pelagic fish in European purse seine fisheries is likely to be in excess of the 10minutes you suggest.  I've only encountered one study relevant study here (Marcalo et al (2006)), which involved looking at stress markers in sardines in Portuguese fisheries sampled throughout the capture process.  That study suggests the capture process can take 90-120minutes from encircling through to the end of transfer fish on board, and and most stress markers seemed to increase throughout time in the net.  Although this point in itself would not change the high-level conclusions (as the key crux for me is how stress of capture compares to the counterfactual death), I do worry your claim here was overconfident and that other arguments you've made in this post might not stand up to scrutiny.

One item I'd like to explore more is whether similar arguments might also apply to slightly larger pelagic forage fish like Mackerel and Herring.  My understanding is by-catch is also relatively low for these species (though they are often captured by pelagic trawlers), but they have a much higher aggregate value and value per fish.  The possibility of developing and implementing humane capture technologies (e.g. electrical stunning) seems greater for these species than for sardines/anchovies, and fewer would need to be consumed to achieve a given level of calories/nutrition.

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!).

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  5^th and 95^th 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.

Thanks for sharing this piece.

From your review, did you get a sense of how many ABFT are farmed at the moment (in terms of number of animals), or how big the industry could get if successful?

Looking very quickly at fishcount's 2017 data, it would suggest 7.4k metric tonnes, but they don't provide a mean slaughter weight.  Based on the weight of a mature adult provided above, it might suggest only around 30k were slaughtered in 2017.  That's seems pretty small for a farmed finfish species.  

All else equal, I'd be surprised that growth since then might make it look like a top priority farmed fish species from a purely scale perspective.  That said its possible the FAO data might not accurately reflect extent of farming, that hatchery mortality rates could be several times higher than for other farmed fish species, and growth could accelerate if there are breakthroughs in farming methods.

Assuming scale in terms of number farmed is relatively small, do you think there would be a case for prioritising allocating resources to improving the welfare this species?

I can see the case that the high-value (both per kg and per animal) of ABFT means that producers might have the financial means to experiment with and implement welfare improvements in a way that might not be true for other fish.  I can also see public campaigns about ABFT farming gathering more support than campaigns about other farmed fish species.

Very interesting.  I'm of Indian origin and was born in the UK.  But my parents were born and grew up in East Africa (Uganda and Kenya).  As vegetarians, we ate a lot of beans/pulses.  It was the norm in our house to soak beans overnight, and also to soak rice prior to cooking. 

Based on my own experience, I'd always assumed that it was common to soak beans in both India and Africa.  So this post is an update for me.  That said, I still believe with around 60% confidence  that soaking is the norm in India (most Indian recipes I've come across suggest soaking).

I think the edits you made to the summary work very well in making it clear what the quantitative analysis does and doesn't cover!  Thank you for taking on board my comments so promptly.

Fully agree with your points on the difficulty of quantifying the indirect benefits, and also how/where those benefits should be attributed.   

I think the challenge is that excluding indirect benefits from a quantitative analysis effectively assigns them a zero value. That is ok when indirect benefits are most likely only a small fraction of the direct benefits.  But it becomes problematic when the indirect benefits could plausibly be several times (or orders of magnitude) larger than the direct ones and relevant to decision-making.

If judgements about the size of the indirect benefits might be important, think it is valuable to make the exclusions clear - as you've now done!

Thanks again for the time you put into the piece, and the clear write-up / reasoning transparency!

Thanks so much for this post.  Very impressive how quickly you put this together. 

I think your analysis is a very helpful take on how cost-effective it might be for advocates to purchase shrimp stunners for industry, and how this might compare to estimates of the cost-effectiveness of historical corporate hen welfare campaigns.  Very useful to try and make different interventions comparable for interested stakeholders.

That said, I think your quantitive analysis probably misses most of the expected value of the SWP’s shrimp stunning intervention.  My guess is that the vast majority of the expected value of this opportunity lies in how much it might bring forward widespread adoption of shrimp stunning by industry, and not the easier-to-quantify short-term direct impacts of the stunners SWP purchases for industry.

I think you recognise this issue in the last paragraph.  And I also fully appreciate that even a relatively shallow attempt at quantifying wide-spread industry adoption scenarios was probably beyond the amount of time you could dedicate to this post.  

That said, I’m not sure this limitation comes through fully in your summary, even after you the updates you added to the top.  My biggest concern is that your report might put off potential donors who might assume your assessment more comprehensively covers benefits than it does, and might not have time to fully engage with your methodology or reach the final paragraph.

If you agree with my assessment, share my concerns, and were open to making changes while fundraising is ongoing, my suggestions would be to be more explicit about the scope limitations of your analysis and how most of the expected value might not be quantified (either by amending the summary or adding an additional update at the top).  When describing the factors that might drive donor decisions, I’d personally also add optimism/pessimism about the potential for this project to bring forward widespread adoption by industry, which I see as independent of the factors you’ve already listed.

If you don’t agree with my assessment about where expected value might come from (e.g. because you think donors purchasing stunners for industry might set a dangerous precedent that might in fact delay adoption), or just happen to be deeply uncertain,  I think it would be great for you to articulate this more explicitly.

Hope you don’t mind me making these suggestions.  Really great work again - thank you for putting the time and effort into it.

Thanks for the helpful comment @Ula Zarosa .  I've now added a  shorter non-technical summary.