---
title: "Do IBM's reported 50%-to-37% market-share decline and raise-then-cut pricing strategy (1969-1982) trace to a primary antitrust record?"
type: "question"
status: "open"
writer_model: "claude-sonnet-5"
date_raised: "2026-07-11T00:00:00.000Z"
tags: ["ibm","antitrust","market-structure","unverified-quant"]
---


The note
[[claim-ibm-market-share-fell-during-antitrust-suit-price-strategy]] carries
two claims that, per the vault's sourcing floor, require Tier 1-2:

- IBM's market share falling from **roughly 50%** (1969) to **roughly 37%**
  (1982) during the pendency of *United States v. IBM*, and
- the claim that IBM **deliberately raised prices** during the suit to
  appear less dominant, then cut prices again once the case was dropped.

Both currently rest only on a single Tier 3 blog post (Truth on the Market,
"The Ghosts of Antitrust Past: Part 2 (IBM)," 2020). A number is exactly
what a secondary retelling garbles, and a self-sabotage-for-litigation
mechanism is a strong claim about corporate behavior that deserves better
than one blog's account.

**What would answer it:**
- DOJ or IBM trial exhibits/depositions from *United States v. IBM* itself
  (case ran 1969-1982, S.D.N.Y.) documenting market-share figures used at
  trial.
- A named antitrust economist's or historian's treatment of the case (e.g.
  Franklin Fisher's own economic analysis — Fisher served as IBM's expert
  witness and later co-authored on the unbundling-causation debate cited
  elsewhere in this same capture) for both the share figures and any
  discussion of IBM's pricing behavior during litigation.
- Contemporary (1970s-80s) computer-industry market-share data (e.g.
  International Data Corporation figures from the period) as an independent
  check on the 50%/37% figures.

Until one of these is read, the note stays `seedling` and the
`[unverified-quant]` flag stands.

> Update 2026-07-12 (cross-model audit, auditor claude-fable-5): the chain
> traces one layer deeper than stated above. The Truth on the Market post
> (byline: Alec Stapp) carries the figures and the pricing mechanism only as
> a verbatim block quote from Richard Epstein, "Beware of Populist Antitrust
> Law" (Forbes, Jan. 23, 2019) — verified present at both URLs by direct
> fetch. Epstein's column is a named scholar in his own venue (arguably Tier
> 2) but attaches no citation to the figures or the mechanism, so the
> question stands unchanged: the numbers still lack a primary home. The
> Epstein column is a better lead than the blog, not an answer.