Does independent evidence support Carragher & Carley's modeled estimate that a full shift to Google AI Overviews would raise US media concentration ~3.4x more than the Paramount–WBD merger did?

media-concentrationai-searchantitrustcorroboration

Carragher and Carley (arXiv:2610.40164, submitted 29 Oct 2026) model a counterfactual: if all US organic search traffic were redistributed in proportion to Google AI Overviews' current citation patterns (holding total traffic constant), their estimate of US media concentration rises by +33.3% — compared to the actual Paramount Skydance/Warner Bros. Discovery merger's measured +9.9% effect on the same traffic-based estimate, i.e. roughly 3.4x the merger's effect. See claim-owner-level-news-concentration-130x-outlet-level and claim-ai-citation-concentration-exceeds-traffic-concentration, the two sibling claims this paper also produced.

This figure is not promoted to its own claim-note for two reasons:

1. It is a modeled scenario, not an observed outcome. The paper's own text says confirming the underlying mechanism — that traffic actually shifts to follow AI citation patterns over time — "requires longitudinal data" the authors do not have. The +33.3%/3.4x figure is the authors' own counterfactual projection under a specific redistribution assumption, not a measured historical effect.
2. The vault's single-source concentration cap. Three other claim-notes already rest on this same unrefereed arXiv preprint (claim-owner-level-news-concentration-130x-outlet-level, claim-ai-citation-concentration-exceeds-traffic-concentration, claim-ai-systems-cite-state-media-more-in-native-language-prompts). Per 00-meta/specs/sources.md's single-source concentration cap, a fourth claim-note from the same primary does not get written until an independent source corroborates the branch.

What would resolve this: an independent author group and venue — not a later paper by Carragher/Carley, not press coverage of the same preprint — either (a) replicating the owner/outlet concentration-index methodology on a comparable dataset, or (b) providing actual longitudinal data on whether search traffic share has moved toward AI-citation-favored outlets since AI Overviews' rollout. Also worth checking periodically: has this preprint been accepted to a refereed venue (as of 2026-10-31 it is arXiv-only, submitted two days prior)?

No candidate next move beyond watching for (a) peer review/acceptance of this preprint, or (b) a second, independently-authored study on AI-citation-driven market concentration.