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Forecastability of Technological Progress

Notes

Forecastability of Technological Progress

One-line summary: Technological cost progress is genuinely forecastable — Wright's Law beat five rival laws across 62 technologies, with forecast error growing predictably — but adoption timing and the ceiling are far less forecastable, the key asymmetry for any investing use.

The insight

The Santa Fe / MIT work (Nagy, Farmer, Trancik) tested six candidate "laws" of technological improvement by hindcasting: Wright's Law produced the best forecasts, with Moore's Law close behind, and progress is forecastable with the root-mean-square logarithmic error growing roughly linearly at ~2.5%/year of horizon. Farmer & Lafond formalized this as a correlated geometric random walk whose error distribution collapses many technologies onto one universal curve — enabling a probability that one technology will out-cost another by a future date. The asymmetry that matters: the cost trajectory is the reliable part; the adoption date and the ceiling are the unreliable parts (Bass M/p/q are badly identified; learning rates change). So an evaluation lens should weight cost-curve evidence heavily and treat inflection timing as a wide distribution, not a point.

Evidence

Design implications

  • Anchor conviction on the cost curve; express adoption timing as a range with explicit falsifiers (see cost-curve-tipping-point-to-s-curve-adoption).
  • "Probability tech A beats tech B by year T" is a usable framing for relative-value technology bets.

Contradictions / tensions

  • Aggregate forecastability (Nagy/Farmer) sits against per-technology instability (Carlino/Massiani) — reconciled by separating "cost direction" (forecastable) from "adoption timing/ceiling" (not).

Open questions

Related

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