We built a browser‑based Monte Carlo model that takes MacKenzie Scott’s $30.3B of 2026‑dollar gifts—inflated from $26.39B nominal 2020‑2025—and allocates them across 13 intervention archetypes. Each archetype draws a cost‑per‑QALY from published causal estimates, shrunk toward zero by study design.

Allocation draws from Scott’s gift database: two‑thirds of the money is disclosed; the rest is imputed from yearly totals weighted by each recipient’s pre‑gift IRS 990 revenue. The Dirichlet centers reflect reported focus areas—health, economic security, education, civic infrastructure, and general community.

The evidence stance slider is the main control. At the skeptical end the model estimates about 70,000 QALYs, each effect weighted by causal credibility; at the credulous end it rises to roughly 200,000 QALYs by trusting every cited effect. That spread, not the dollar figure, drives uncertainty.

Because Scott’s portfolio focuses on economic mobility, education, and equity—areas with little causal evidence linking them to QALYs—the model under‑states her total social impact. The output answers the specific question: how many quality‑adjusted life‑years does her giving buy, given the available health‑intervention evidence.