Wright's law: unit cost falls a constant fraction with every doubling of cumulative production

Wright's law — also called the experience curve or learning curve — states that as cumulative production of a good doubles, its unit cost falls by a constant percentage, the "progress ratio": "if the progress ratio is 0.8 ... the unit cost is 80% of what it was before" each time cumulative output doubles. Under competition, price tracks cost down continuously across the whole scaling trajectory, rather than holding at an old level until a late collapse.

This is the proposed general mechanism behind two documented monotonic-decline cases: claim-aluminium-price-fell-monotonically-after-hall-heroult (Hall-Héroult aluminium, 1880s–90s) and claim-inference-cost-collapsed-280x (AI inference, 2022–2024). It is the structural opposite of the hold-then-collapse shape predicted for asteroid-mined platinum-group metals in claim-asteroid-pgm-price-holds-then-collapses — see claim-cheaper-extraction-disruptions-fall-monotonically-not-hold-then-collapse for the synthesis across all three.

[unverified-mechanism — needs primary]. Both cited restatements (New Things Under the Sun, Our World in Data) are secondary explainers, not the originating economic literature — T.P. Wright's 1936 aircraft-manufacturing cost paper, or the Boston Consulting Group's original 1960s–70s experience-curve studies. Per the vault's sourcing floor, a specific technical-mechanism claim needs a Tier 1–2 primary; a named-analyst blog post and a data-journalism explainer clear the floor for "what is this concept" but not yet for "this is exactly how it works and how well it's supported empirically." Verification routed to question-verify-wrights-law-primary-source — partially answered by claim-sahals-identity-equates-wrights-law-and-moores-law, a Tier 1 primary (Lafond et al. 2017) that empirically tests this mechanism, though it is not the 1936 Wright original the question asks for.