Our team has fairly recently done pretty similar work to what you are describing. You can see it here http://​​www.charityentrepreneurship.com/​​blog/​​from-humans-in-canada-to-battery-caged-chickens-in-the-united-states-which-animals-have-the-hardest-lives-results
Well thanks that’s neat, I would sooner use that than the other estimates, but it seems that you are equally assuming that scales go from equal positive and negative extremes. E.g., no disease is +17 but severe disease is only −17.
Our team has fairly recently done pretty similar work to what you are describing. You can see it here http://​​www.charityentrepreneurship.com/​​blog/​​from-humans-in-canada-to-battery-caged-chickens-in-the-united-states-which-animals-have-the-hardest-lives-results
Well thanks that’s neat, I would sooner use that than the other estimates, but it seems that you are equally assuming that scales go from equal positive and negative extremes. E.g., no disease is +17 but severe disease is only −17.