Shrimp Welfare Project’s ranges are narrower for a few reasons. Because SWP works directly with farmers, they can track and estimate the number of shrimp on partner farms, reducing uncertainty about the animals affected. We also either used point estimates or narrow ranges for other parameters, such as the duration of impact (based on the lifespan of electrical stunners) and the duration of improved water quality. This means the main source of uncertainty in SWP’s CEA lies in the SADs estimates, whereas other charities’ CEAs combine multiple uncertain parameters that multiply into wider ranges.
Adding uncertainty ranges to SADs would be complex, since it would involve modeling variation in welfare ranges, sentience, pain severity, and/or moral weights between pain types. We’ve chosen not to include ranges so far because of time constraints and because the final estimates are already quite broad. If we do so in the future, we’d collaborate with the organizations that produced the original SADs estimates to make sure that uncertainty is modeled appropriately.
Thanks for the positive feedback!
Shrimp Welfare Project’s ranges are narrower for a few reasons. Because SWP works directly with farmers, they can track and estimate the number of shrimp on partner farms, reducing uncertainty about the animals affected. We also either used point estimates or narrow ranges for other parameters, such as the duration of impact (based on the lifespan of electrical stunners) and the duration of improved water quality. This means the main source of uncertainty in SWP’s CEA lies in the SADs estimates, whereas other charities’ CEAs combine multiple uncertain parameters that multiply into wider ranges.
Adding uncertainty ranges to SADs would be complex, since it would involve modeling variation in welfare ranges, sentience, pain severity, and/or moral weights between pain types. We’ve chosen not to include ranges so far because of time constraints and because the final estimates are already quite broad. If we do so in the future, we’d collaborate with the organizations that produced the original SADs estimates to make sure that uncertainty is modeled appropriately.