Hey Vasco! Interesting question, unfortunately I don’t know the answer...
My sense is no, as you say, the intervention increases costs without an increase in productivity for the producers. But ultimately an incentive here is continued market access, which I’m sure an economist could model whether or not this could lead to an increase in the number of shrimps (over time).
Another point to emphasise though—it’s my sense that the intervention should be modelled as electrical stunning replaces air asphyxiation, rather than (perfectly implemented) ice slurry. Ice slurry slaughter is just a very difficult thing to do correctly in practice (and I’ve not seen it happen) - as even if at some point the shrimps are submerged in ice for a short period of time, it’s often not long enough to kill them (~30seconds).
Another point to emphasise though—it’s my sense that the intervention should be modelled as electrical stunning replaces air asphyxiation, rather than (perfectly implemented) ice slurry.
Do you think it would be best for me to assume than 100 % of the shrimp helped are originally being slaughtered via air asphyxiation? I am currently assuming 62.5 % are originally being slaughtered via air asphyxiation, and the other 37.5 % via perfectly implemented ice slurry, but this seems way too high considering you have not seen it happen.
I would probably model it with https://www.getguesstimate.com/ to give a range of uncertainty in the numbers. But yeah it wouldn’t surprise me if the number was ~100%
Thanks. I will update the analysis using 95 % (= (0.9 + 1)/2), which results in the same expected cost-effectiveness as using a uniform distribution ranging from 90 % to 100 %.
Another point to emphasise though—it’s my sense that the intervention should be modelled as electrical stunning replaces air asphyxiation, rather than (perfectly implemented) ice slurry. Ice slurry slaughter is just a very difficult thing to do correctly in practice (and I’ve not seen it happen) - as even if at some point the shrimps are submerged in ice for a short period of time, it’s often not long enough to kill them (~30seconds).
I accounted for badly implemented ice slurry slaughter. I assumed:
All of the shrimps helped transition to electrical stunning, 62.5 % (= 1 − 0.375) from air asphyxiation, and 37.5 % from ice slurry (= 0.75*0.5). I got these fractions assuming 75 % of the targeted producers use some form of ice slurry, half of those implement it properly, and the other half improperly to the point of it being practically equivalent to air asphyxiation. I made these assumptions having in mind Aaron’s comment at the end of this section.
In any case, based on my assumptions, it does not matter whether HSI is harmful for the 37.5 % of the affected shrimp which go from well implemented ice slurry to electrical stunning slaughter. The overall cost-effectiveness is dominated by making 62.5 % of the affected shrimp go from air asphyxiation to electrical stunning slaughter. I estimate 97.3 % (= 0.625*0.0447/0.0287) of the benefits come from helping shrimp slaughtered via air asphyxiation, and that the increase in welfare for these is 48.6 % (= 1 − 4.85/9.44), whereas the number of shrimp would very hardly increase by that. So the question of whether the number of shrimp increases is only relevant if a very small fraction of the helped shrimp is slaughtered via air asphyxiation (again, conditional on my assumptions).
Hey Vasco! Interesting question, unfortunately I don’t know the answer...
My sense is no, as you say, the intervention increases costs without an increase in productivity for the producers. But ultimately an incentive here is continued market access, which I’m sure an economist could model whether or not this could lead to an increase in the number of shrimps (over time).
Another point to emphasise though—it’s my sense that the intervention should be modelled as electrical stunning replaces air asphyxiation, rather than (perfectly implemented) ice slurry. Ice slurry slaughter is just a very difficult thing to do correctly in practice (and I’ve not seen it happen) - as even if at some point the shrimps are submerged in ice for a short period of time, it’s often not long enough to kill them (~30seconds).
Do you think it would be best for me to assume than 100 % of the shrimp helped are originally being slaughtered via air asphyxiation? I am currently assuming 62.5 % are originally being slaughtered via air asphyxiation, and the other 37.5 % via perfectly implemented ice slurry, but this seems way too high considering you have not seen it happen.
I would probably model it with https://www.getguesstimate.com/ to give a range of uncertainty in the numbers. But yeah it wouldn’t surprise me if the number was ~100%
Thanks. I will update the analysis using 95 % (= (0.9 + 1)/2), which results in the same expected cost-effectiveness as using a uniform distribution ranging from 90 % to 100 %.
Thanks, Aaron.
I accounted for badly implemented ice slurry slaughter. I assumed:
In any case, based on my assumptions, it does not matter whether HSI is harmful for the 37.5 % of the affected shrimp which go from well implemented ice slurry to electrical stunning slaughter. The overall cost-effectiveness is dominated by making 62.5 % of the affected shrimp go from air asphyxiation to electrical stunning slaughter. I estimate 97.3 % (= 0.625*0.0447/0.0287) of the benefits come from helping shrimp slaughtered via air asphyxiation, and that the increase in welfare for these is 48.6 % (= 1 − 4.85/9.44), whereas the number of shrimp would very hardly increase by that. So the question of whether the number of shrimp increases is only relevant if a very small fraction of the helped shrimp is slaughtered via air asphyxiation (again, conditional on my assumptions).