Do IBM's reported 50%-to-37% market-share decline and raise-then-cut pricing strategy (1969-1982) trace to a primary antitrust record?

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.