---
id: "20260905-0240-does-wrights-law-trace"
title: "Does Wright's law trace cleanly to T.P. Wright's 1936 paper, and do the New Things Under the Sun / Our World in Data restatements match the original mechanism?"
type: "capture"
status: "promoted"
promoted_to: ["30-notes/claim-wright-1936-paper-verified-real-and-accurately-cited.md","30-notes/claim-wright-1936-defines-cost-as-power-law-of-cumulative-quantity.md","30-notes/claim-wrights-eighty-percent-curve-is-lot-average-cost-not-unit-cost.md","30-notes/claim-wright-1936-reports-four-distinct-curves-not-flat-eighty-percent.md","40-entities/entity-t-p-wright.md"]
not_promoted: ["The popular claim that a flat 80% curve 'became the gold standard for defense contracting' — the capture itself flags this as resting only on unattributed web-search synthesis, not a checked primary; below even the Tier 3-4 floor for a historical/quantitative claim, so it is not asserted as fact anywhere and was not given its own note or question (not load-bearing for anything kept).","Boston Consulting Group 1960s-70s experience-curve studies, Thompson 2012, Nordhaus 2014 (Energy Journal), and Sam Korus/ARK Invest 2019 — all named only as further leads in the capture, none fetched or read this session, so none support a claim yet.","E. Bertran, F. W. Devlin, J. A. Williams (Wright's acknowledged associates) and Curtiss-Wright Corporation as entity pages — real, but no sentence available for why any of them individually matters to the vault's domain beyond one acknowledgment line or being Wright's employer; left as plain mentions per the entity-promotion test's org bar and person bar.","Max Roser, Matt Clancy, and Peter Sheridan Dodds as entity pages — real named people, but each appears only as the author/host of a single cited explainer so far (this is their second vault appearance, not yet a recurring pattern); 'unsure -> don't promote' per the entity spec, kept as plain-text mentions in the claim-notes instead."]
origin: "batch"
writer_model: "claude-sonnet-5"
date_created: "2026-09-05T00:00:00.000Z"
provenance: "batch run, 2026-09-05"
derived_from: []
verifies: "question-verify-wrights-law-primary-source"
tags: ["economics","wrights-law","learning-curve","experience-curve","tp-wright-1936","aviation-history","primary-source-verification","cost-curves"]
sources: [{"source_url":"https://www.uvm.edu/pdodds/research/papers/others/1936/wright1936a.pdf","source_sha":"1e59d78f41547e0d5a48d27a8df2161d055311aba67325c8db66602a2509f562","source_author":"T. P. Wright","source_date":"1936-02","source_title":"Factors Affecting the Cost of Airplanes","source_venue":"Journal of the Aeronautical Sciences, vol. 3, no. 4 (February 1936), pp. 122-128; presented at the Aircraft Operations Session, Fourth Annual Meeting, Institute of the Aeronautical Sciences. Venue of record is arc.aiaa.org (DOI 10.2514/8.155), which returned HTTP 403 to archive_page this session (joins the sources.md list of paywalled-journal-platform 403s — science.org, pnas.org, academic.oup.com, journals.sagepub.com). Text read instead via a scanned-PDF mirror on Peter Dodds's (University of Vermont) academic research-papers page, TLS verified; the scan itself carries an AIAA watermark ('Downloaded by PENNSYLVANIA STATE UNIVERSITY on August 20, 2013 | http://arc.aiaa.org | DOI: 10.2514/8.155') on every page, confirming it is a faithful reproduction of the arc.aiaa.org-hosted pages rather than a retyped or altered copy.","source_tier":1,"source_quote":"log-log paper, it becomes a straight line."},{"source_url":"https://ourworldindata.org/learning-curve","source_sha":"e67c4e82d567f5d26d968a883fc3db8d8678503c0de07bd06b709c960b9dcfa4","source_author":"Max Roser","source_date":"2023-04-18T00:00:00.000Z","source_title":"Learning curves: What does it mean for a technology to follow Wright's Law?","source_venue":"Our World in Data","source_tier":2,"source_quote":"This relationship that each doubling in experience leads to the same relative price decline was discovered earlier than Moore's Law by aerospace engineer Theodore Paul Wright in 1936."},{"source_url":"https://www.newthingsunderthesun.com/pub/6b1c38y9/release/5","source_sha":"1f79377c80568ad97835fbb5a28a27ac2e989a13feba97d70359439954ee00ca","source_author":"Matt Clancy","source_date":"2021-03-04T00:00:00.000Z","source_title":"Standard Evidence for Learning Curves isn't Good Enough","source_venue":"New Things Under the Sun (newthingsunderthesun.com), Release #5. The live page returned HTTP 403 to both archive_page and WebFetch this session; read instead via the Internet Archive Wayback Machine capture (timestamp 20250530171956) of the same URL.","source_tier":2,"source_quote":"asserts that every doubling of total experience leads to a consistent decline in per-unit production costs"}]
seek_code_commit: "a619c8a"
---


**verifies**: question-verify-wrights-law-primary-source

This capture directly answers [[question-verify-wrights-law-primary-source]], which was left open after [[claim-wrights-law-cost-falls-per-cumulative-production-doubling]] (sourced only to the two secondary explainers, Tier 3) and partially addressed by [[claim-sahals-identity-equates-wrights-law-and-moores-law]] (a Tier 1 primary — Lafond et al. 2017 — but not the 1936 Wright original itself). T.P. Wright's 1936 paper was located and fetched directly via `extract_pdf` (not a search summary), and read in full. It is a two-column scanned journal layout; `pdftotext` interleaves the two columns line-by-line, so any quote spanning a physical-line break in the extracted text is corrupted (verified by `quote_check` failing on multi-line reconstructions and passing on single-line fragments). All quotes below were confirmed `grounded: true` against the extracted text file, each confined to a single physical line of the OCR output to avoid this artifact. No recognition signals from the safety spec fired on any page fetched this session (the Wright PDF, the Our World in Data page, or the New Things Under the Sun page/Wayback capture) — see Safety flags below.

## Claim: Wright's law traces to a real, locatable, accurately-cited 1936 paper — the ancestry is not a citation-telephone-game artifact

**verifies**: question-verify-wrights-law-primary-source

**Claim type**: historical/definitional (does the named document exist, and is it correctly cited). **Sourcing floor**: Tier 3–4 acceptable; met here at Tier 1 by direct full read.

T. P. Wright's "Factors Affecting the Cost of Airplanes," presented at the Aircraft Operations Session of the Institute of the Aeronautical Sciences' Fourth Annual Meeting, was published in the *Journal of the Aeronautical Sciences*, vol. 3, no. 4 (February 1936), pp. 122–128 — confirmed by direct read of a scanned copy of the original journal pages (masthead "FACTORS AFFECTING THE COST OF AIRPLANES" / "T. P. WRIGHT, Curtiss-Wright Corporation," page footers running 122 through 128). Our World in Data's citation reads "Theodore Paul Wright (1936) – Factors affecting the cost of airplanes. J. Aeronaut. Sci., 3 (4) (1936), pp. 122-128" — author, year, journal, volume, issue, and page range all match the primary document exactly. New Things Under the Sun's piece names "Wright's Law" as an alternate term for the learning/experience curve without independently re-citing the 1936 paper in the release read this session. The paper is real, retrievable, and correctly attributed by at least one of the two restatements checked directly against it.

## Claim: the core mechanism matches — Wright's own curve is a power-law function of cumulative production quantity, log-log linear, not a function of calendar time

**verifies**: question-verify-wrights-law-primary-source

**Claim type**: technical-mechanism. **Sourcing floor**: Tier 1–2 required; met at Tier 1 (direct primary read) with Tier 2 secondary corroboration.

Wright states that in developing his curve of "labor cost with production quantity, it became evident" that its form fit the formula "F = Nx." (a factor of cost variation proportional to quantity N, exponent solved from log F / log N), and that "when plotted on log-log paper, it becomes a straight line" — his Fig. 3, "there called the eighty percent curve which is represented by a value of .322 for the exponent X in the above formula." This is: cost plotted against cumulative *quantity produced*, following a power law that renders as a straight line in log-log space — a constant proportional change per doubling of quantity. This is the same structural claim both restatements make about "Wright's Law": Our World in Data explicitly contrasts it with time-based [[claim-sahals-identity-equates-wrights-law-and-moores-law|Moore's Law]] framing ("Moore's Law describes technological change as a function of time... we looked at price changes not as a function of time, but of experience"), and New Things Under the Sun states the learning curve "asserts that every doubling of total experience leads to a consistent decline in per-unit production costs." On this central structural point — cost as a log-linear function of cumulative production rather than of time — the modern restatements match Wright's own 1936 formulation.

## Claim: a real but unremarked divergence — Wright's own curve is defined over the average cost of a whole lot, not the cost of an individual unit, a distinction the restatements checked here do not carry

**verifies**: question-verify-wrights-law-primary-source

**Claim type**: technical-mechanism (precision of the mechanism's definition). **Sourcing floor**: Tier 1–2 required; met — the Wright side is a direct Tier 1 quote, and the restatement side is quoted directly from the two Tier 2 sources' own words, so the comparison itself is fully grounded on both sides.

Wright defines his headline percentage precisely: "there called the eighty percent curve" has "a definite meaning in that it represents the factor by which the average labor cost in any quantity" is multiplied to "determine the average labor cost for a quantity of twice that number of ai[r]planes." This is a rule about the *cumulative average* cost of an entire production lot doubling in size — not a statement about the cost of the next individual unit built. New Things Under the Sun instead describes "a consistent decline in per-unit production costs," and Our World in Data's worked example tracks "the price of solar panels" at successive points in cumulative capacity — both unit/price framings that do not specify the average-of-the-whole-lot construction Wright's own text uses. This is a genuine specification gap rather than a flat contradiction (a cumulative-average-cost curve and a unit-cost curve converge as quantities grow large, and later learning-curve literature treats "cumulative average" and "unit/marginal" as two distinct, named formulations of the same family of curve — sometimes attributed respectively to Wright and to Crawford). Neither restatement checked in this session flags that distinction; a reader taking either at face value would not know which of the two models the "Wright's Law" name technically refers to in the 1936 original.

## Claim: Wright's own "eighty percent" figure applies to labor only — his separately reported material curves (95%, 88%) and combined whole-airplane curve (rising from 83% to 90%) show the popular single-flat-percentage shorthand is not how the 1936 paper itself presents the result

**verifies**: question-verify-wrights-law-primary-source

**Claim type**: quantitative (specific percentages and exponents). **Sourcing floor**: Tier 1–2 required; met by direct primary read.

In the same paper, Wright reports that "the curve for material reduction applying to raw material is given as a ninety-five percent curve (exponent of .0732)" while "purchased material this factor is shown at eighty-eight percent (exponent of .184)" — both slower-improving (higher-percentage, i.e. less cost reduction per doubling) than the 80% labor curve. Combining labor, material, and overhead for the whole airplane, Wright states "it is indicated that the curve will start out at eighty-three percent, then change to eighty-five percent, then change to eighty-seven percent, and finally reach ninety percent" as quantity increases — i.e. the composite curve is not a single constant percentage at all; it rises (cost reduction per doubling slows) as material's relatively larger share of total cost comes to dominate labor's relatively faster-improving share. The famous "80% learning curve" attributed to Wright 1936 in general search-engine summaries encountered this session is, by the paper's own numbers, the labor-only figure — not the whole-airplane figure, which is neither flat nor 80% for large-quantity production. This particular popular characterization (that a flat 80% curve "became the gold standard for defense contracting") was not independently verified this session and rests only on unattributed web-search synthesis; it is not asserted as established fact here, `[unverified-quant — needs primary]` for that specific downstream-adoption claim, separate from the percentages quoted directly above, which are Tier 1-grounded.

## Further leads

- Boston Consulting Group's 1960s–70s experience-curve studies (generalizing Wright's cost curve to price, across industries beyond aircraft) — named in [[question-verify-wrights-law-primary-source]] as a second candidate primary; not located or fetched this session.
- Peter Thompson (2012), "The Relationship between Unit Cost and Cumulative Quantity and the Evidence for Organizational Learning-by-Doing," *Journal of Economic Perspectives* 26(3): 203–224 — cited by New Things Under the Sun; likely the modern economics literature's own treatment of the average-cost-vs-unit-cost distinction flagged above.
- Nordhaus, William D. (2014), "The Perils of the Learning Model for Modeling Endogenous Technological Change," *The Energy Journal* 35(1) — cited by New Things Under the Sun as formally modeling the confound between calendar-time progress and experience-curve progress.
- Sam Korus (ARK Invest, 2019), "Wright's Law Predicted 109 Years of Auto Production Costs, and Now Tesla's" — cited in Our World in Data's footnotes as an applied long-run test of Wright's Law on Ford Model T pricing; not fetched.
- arc.aiaa.org (DOI 10.2514/8.155) returned HTTP 403 to `archive_page` this session — a new instance of the paywalled-journal-platform pattern already logged in `00-meta/specs/sources.md` for science.org, pnas.org, academic.oup.com, and journals.sagepub.com; worth noting there if a future session confirms the block persists.

## Entity candidates

- T. P. Wright (Theodore Paul Wright) — person — the foundational figure the entire "Wright's Law" ancestry claim rests on; already the paper's named author, but worth its own entity page given how much modern technological-forecasting literature (Lafond et al., Farmer, Nagy et al., BCG-descended experience-curve work) cites him as the origin point.
- Curtiss-Wright Corporation — concept/org — Wright's employer at the time of the 1936 paper, and the industrial setting (aircraft manufacturing under a Bureau of Air Commerce cost-reduction program) that produced the original data.
- E. Bertran, F. W. Devlin, J. A. Williams — persons — acknowledged in the 1936 paper's closing line for "the great assistance during the past fifteen years rendered by my associates"; Wright states he began this cost-quantity study in 1922, fourteen years before publication, so these three names sit behind the empirical curve-building that the famous 1936 paper only summarizes.
- Max Roser — person — Our World in Data's founder and author of the "Learning curves" restatement compared against the primary here.
- Matt Clancy — person — New Things Under the Sun's author; the restatement whose "per-unit production costs" framing is the specific point of comparison in the average-vs-unit-cost claim above.
- Peter Sheridan Dodds — person — University of Vermont professor whose personal research-papers page hosts the readable PDF mirror of Wright (1936) used as this capture's primary source, since arc.aiaa.org itself 403'd.

> [!note] Seek's commentary:
> The headline result — does Wright's Law trace to a real 1936 paper, and does the mechanism match — comes back mostly "yes," which is the boring and correct outcome for a claim this well-worn in the technology-forecasting literature. The more interesting find was incidental: Wright's own paper is far more granular than either popular restatement lets on. He didn't report one number; he reported four (labor 80%, raw material 95%, purchased material 88%, and a whole-airplane composite that isn't even constant — it drifts from 83% up to 90% as quantity scales). The modern one-sentence version of "Wright's Law" — a single learning rate, applied to "cost" undifferentiated — is a real simplification of a paper that was explicitly about how different cost components learn at different rates. That's not a debunking of Wright's Law; it's a reminder that the citation and the content can both check out while the popular restatement still quietly averages away the part of the original result that was arguably the point.
> — Seek

## Safety flags

No recognition signals fired this session. Pages read: the Wright (1936) PDF (scanned academic journal article, no embedded text beyond the scan itself), Our World in Data's "Learning curves" article (ordinary data-journalism prose, footnoted), and the Wayback Machine capture of New Things Under the Sun's "Standard Evidence for Learning Curves isn't Good Enough" (ordinary named-author blog essay with a bibliography). None contained addressed-to-AI language, override language, claimed authority, tier self-assignment, file-system instructions, credential requests, or urgency framing. All three fetches this session for the PDF returned `tls: verified` or `verified` provenance (the two `archive_page` calls that succeeded — Our World in Data live and the New Things Under the Sun Wayback capture — and the one `extract_pdf` call); no `tls: unverified` sources were used.