The one controlled test we know of is Ahrefs' study, reported by Search Engine Journal on 11 May 2026. Ahrefs took 1,885 pages that added JSON-LD, matched each against three control pages with similar citation levels that never added it, and compared citations 30 days before and after. The result for Google AI Overviews was a 4.6% decline relative to controls, small but outside noise; for Google AI Mode a 2.4% rise and for ChatGPT a 2.2% rise, both too small to distinguish from random variation. The article's summary: "No platform showed a meaningful citation increase after schema was added."
Two caveats come with it. Every page in the test already had more than 100 AI Overview citations, so the study says nothing about pages that are not yet cited. And in a separate look at 6 million URLs, pages cited by AI were about three times more likely to carry JSON-LD, which Ahrefs treats as correlation: the kind of site that adds schema is the kind of site that gets cited.
Google's own guidance on AI features says: "You don't need to create new machine readable files, AI text files, or markup to appear in these features", and "There's also no special schema.org structured data that you need to add". Its one recommendation is to keep structured data matching the visible text.
What to do
Keep the markup you have accurate and matching the page. Add Article or FAQPage data if it mirrors what visitors see, as the pages on this site do, because it costs nothing and helps ordinary search features. Then spend the time where the citation decision is made: a title that matches the question, the answer in the first paragraph, facts with dates, and sources. Schema describes a page; it does not make it the best answer.
