1) As you correctly observed, we didn’t adjust welfare points for population size and odds of feeling pain in this spreadsheet. But we just publish another report summarizing our animal prioritization research where we aggregated information about baseline welfare points, population size, odds of feeling pain, neglectedness, and amount of suffering caused by a smaller number of specific reasons.
Generally, when we are calculating the cost-effectiveness of a given intervention we take into account the number of welfare points “gained” (baseline welfare points changed counterfactually by the intervention) multiplied by odds of feeling pain and number of animals affected.
We also need to adjust for length of life. For example, if the baseline welfare points per year for a cow is −20 and for broiler chicken is −56, but beef cow spends 402 days on a farm, their WP would be multiplied by the percentage of year they spend on the farm, so 402 days / 365 days in a year = 110%, and broiler chicken spend 42 days, then WPs would be multiplied by 12% resulting in: Cow: −22 welfare points per lifetime of an individual Broiler chicken: −6.72 welfare points per lifetime of an individual.
2) The range is the minimum and maximum values of welfare points as rated by our external reviewers. “Total welfare score” (second column) is an average of internal and external reviewer’s ratings.
1) As you correctly observed, we didn’t adjust welfare points for population size and odds of feeling pain in this spreadsheet. But we just publish another report summarizing our animal prioritization research where we aggregated information about baseline welfare points, population size, odds of feeling pain, neglectedness, and amount of suffering caused by a smaller number of specific reasons.
Generally, when we are calculating the cost-effectiveness of a given intervention we take into account the number of welfare points “gained” (baseline welfare points changed counterfactually by the intervention) multiplied by odds of feeling pain and number of animals affected.
We also need to adjust for length of life. For example, if the baseline welfare points per year for a cow is −20 and for broiler chicken is −56, but beef cow spends 402 days on a farm, their WP would be multiplied by the percentage of year they spend on the farm, so 402 days / 365 days in a year = 110%, and broiler chicken spend 42 days, then WPs would be multiplied by 12% resulting in:
Cow: −22 welfare points per lifetime of an individual
Broiler chicken: −6.72 welfare points per lifetime of an individual.
2) The range is the minimum and maximum values of welfare points as rated by our external reviewers. “Total welfare score” (second column) is an average of internal and external reviewer’s ratings.