The effective altruism movement has substantially influenced animal welfare philanthropy and advocacy by applying cost-effectiveness analysis to welfare interventions.
The application of effective altruism principles to animal welfare has had substantial practical effects on how advocacy resources are allocated. By asking which interventions help the most animals per dollar, EA analysis has directed funding toward corporate campaigns with documented outcomes, international advocacy in countries with large farming sectors, and organisations with strong monitoring and evaluation practices. Critics argue that cost-effectiveness framing can undervalue structural change and movement building that is hard to quantify. EA engagement with wild animal welfare and invertebrate welfare has opened important discussions about the moral status of enormous numbers of beings that receive almost no attention in conventional animal advocacy. Whatever its limitations, EA has introduced rigour and strategic thinking to animal welfare philanthropy that was previously largely absent.