I think the idea of this calculator is pretty good, but the implementation pulls some pretty questionable moves which in aggregate make it quite misleading (perhaps multiple orders of magnitude).
Some of the concerns (robustness of cost-effectiveness estimate; switch between pig lives and all animal lives; distinction between saving lives and averting them) have been highlighted by others. Two other serious ones:
1) Adding “once off situation, if you were the only one who could do so” to the question about saving a human’s life. These conditions don’t apply to the animal lives in consideration later. There is a case that that shouldn’t make a difference, but I think this is controversial, and to the extent that it shouldn’t make a difference I think you shouldn’t include the condition when asking about human lives.
2) Switching between trade-off rates for time-suffering between humans and pigs and trade-off rates for saving lives. Since humans live many times longer (very roughly one hundred times longer) than pigs who are raised for meat, just on suffering terms you might get quite a large factor of divergence when you do this conversion. Additionally, when thinking about saving lives instrumental effects may be more important to our judgements than when comparing suffering, and this could further skew the conversion. You could correct for this by asking about the trade-offs between lives directly, or asking about trade-offs between suffering and saving/averting lives.
I think the idea of this calculator is pretty good, but the implementation pulls some pretty questionable moves which in aggregate make it quite misleading (perhaps multiple orders of magnitude).
Some of the concerns (robustness of cost-effectiveness estimate; switch between pig lives and all animal lives; distinction between saving lives and averting them) have been highlighted by others. Two other serious ones:
1) Adding “once off situation, if you were the only one who could do so” to the question about saving a human’s life. These conditions don’t apply to the animal lives in consideration later. There is a case that that shouldn’t make a difference, but I think this is controversial, and to the extent that it shouldn’t make a difference I think you shouldn’t include the condition when asking about human lives.
2) Switching between trade-off rates for time-suffering between humans and pigs and trade-off rates for saving lives. Since humans live many times longer (very roughly one hundred times longer) than pigs who are raised for meat, just on suffering terms you might get quite a large factor of divergence when you do this conversion. Additionally, when thinking about saving lives instrumental effects may be more important to our judgements than when comparing suffering, and this could further skew the conversion. You could correct for this by asking about the trade-offs between lives directly, or asking about trade-offs between suffering and saving/averting lives.
Thanks for your comments, see my other responses, particularly around the question of rigour vs. impact.