A large and growing body of high-quality research shows that increased school funding improves student outcomes. A new Brookings Institute report examines this relationship but finds much smaller effects than a recent, widely cited meta-analysis. However, because the report relies on statewide averages for spending and outcomes, it masks substantial within-state variation. And unlike the studies in the meta-analysis, its simplistic methods cannot credibly estimate the true funding–outcomes relationship. As a result, the report offers little meaningful guidance for policymakers seeking to reform school funding policies.