I have been drawn to animal welfare interventions due to cost-effectiveness analyses consistently suggesting they are much more cost-effective than ones in global health and development. I think the 1st analysis I found along these lines was that from Stephen Clare and Aidan Goth, whose probabilistic model suggests The Humane League (THL) is 926 (= 25/0.027) times as cost-effective as the Against Malaria Foundation (AMF).