Suppose, hypothetically, we found that providing one guide dog (at a cost of $50,000) would give a 10% increase in reported wellbeing for one person’s life over nine years (the working life of the dog). That would be 0.9 WALYs. And suppose that providing 5,000 books (at a cost of $50,000) provided a 0.001% increase in quality of life for 500 people for forty years. That would be 2 WALYs. If we knew this, then we’d know that spending $50,000 on schoolbooks provided a greater benefit than spending $50,000 on one guide dog.
