- A model estimates MacKenzie Scott's $26.3B philanthropy buys 70,000 to 200,000 QALYs, depending on evidence stance.
- Key uncertainty is evidence stance, not dollar amount, with skeptical weighting reducing effectiveness estimates.
- The model compares Scott's giving to global health frontier, which is ~1,500x more cost-effective per marginal dollar.
- Most of Scott's giving targets non-health areas like equity and education, so QALY model understates total social impact.