WALYs — Welfare-Adjusted Life Years — are an emerging framework that attempts to quantify animal welfare across populations, enabling comparison of interventions by their welfare impact.
The WALY framework represents an attempt to bring the same rigour to animal welfare prioritisation that cost-effectiveness analysis has brought to global health. Even imprecise welfare impact estimates can improve prioritisation over purely intuitive approaches. The framework forces explicit engagement with difficult questions: How severe is this suffering relative to that? How many animals are affected? How long does it last? Making these assumptions explicit allows them to be debated, refined, and improved.