--- image: "/images/notes/midgley-productivity-externalities.jpg" title: "Thomas Midgley Jr. and the Limits of 'Productivity-Raising'" date: 2026-04-18 url: "https://x.com/ccatalini/status/2045595151633166546" tags: ['ai-agi'] deck: "Leaded gasoline and CFCs were obviously good by the productivity standard. 'Productivity-raising input' describes a transition — not its externalities." tweetCount: 3 likes: 3 reposts: 1 --- Thomas Midgley Jr. invented two of the most productivity-raising, competitively-produced inputs of the 20th century: leaded gasoline and CFCs. Both were obviously good by that standard. One poisoned three generations. The other punched a hole in the ozone layer. More intelligence will make us richer, healthier, better taught. Kevin is right about that. But "productivity-raising input" describes a transition, not a destination — and every transition relocates value before it expands it. [x.com](https://x.com/Afinetheorem/status/2045506796224499835?s=20) Verification has to scale with capability. Burden-of-proof arguments only work when the proof arrives in time. Midgley's didn't.