reply There’s a bunch of interesting work on this. A sample at the end. I want a measure more connected to physics. Energy, productive capabilities, etc. something more Kardashev Scale inspired but practical for decisions today. There’s solid attempts at measures based on energy, energy, work (physics work) economic measures, but none that I’ve seen take into account the growth of knowledge well, which is (imo) more fundamental to modern economic growth than traded commodities. My LLM friends haven’t found great measures, but one did propose a neat measure called Reach: (log number of future states a civilization can reach) + an approximation using useful work, compressed world models, and populations of entities. Reach: claude.ai/public/artifac… (photos below, portrait because landscape didn’t render well on phone). Other works: 1.1964 — Kardashev scale. Capability as energy commanded; Sagan's 1973 interpolation made it continuous (Earth ≈ 0.73). 2.1972 — Measure of Economic Welfare (Nordhaus & Tobin). GDP rebuilt as welfare: add leisure and household work, subtract regrettables. On the ISEW page. 3.1990 — Human Development Index (Sen, ul Haq). Capability as a number: longevity, schooling, income. 4.1990 — Kaya identity. Emissions = population × GDP per capita × energy intensity × carbon intensity. The decomposition behind every decarbonization target. 5.1995 — Genuine Progress Indicator. The monetary-adjustment line matured; the one governments compute. 6.2009 — Stiglitz–Sen–Fitoussi Commission. The case that no scalar suffices; the dashboard framing since. 7.2009 — Useful work accounting (Ayres & Warr). Growth as exergy converted to work; exergy efficiency as the sector-level Kardashev number. 8.2012 — Inclusive Wealth Index (Arrow, Dasgupta, UNEP). Value as a stock: produced, human, natural capital at shadow prices. 9.2019 — GDP-B (Brynjolfsson et al.). Willingness-to-accept for losing free goods, added to GDP. The zero-price fix. NBER w25695. 10.2021 — The Dasgupta Review. Inclusive wealth with institutional teeth, commissioned by the UK Treasury