Original title: Who Anchors AI Overviews in Health? Baidu, Google, and the Geography of Authority
Mingyue Zha, Ho-Chun Herbert Chang · September 2026
Search engines now use artificial intelligence to generate quick health summaries, but we do not fully know what sources they rely on across different places. Researchers audited AI overviews on Google and Baidu to see what links and information they present. They ran health searches across multiple countries and languages to trace where the answers come from. They found that both companies favor their own platforms over a varied mix of original sources. Furthermore, smaller countries with lower localization get fewer local references. Searching in a local official language instead of English multiplies local sources several times over. Finally, health disclaimers change depending on language, culture, and topic severity, showing a need for culturally-aware oversight.
You walk into a library and ask for health information. The librarian, instead of pointing you to a variety of medical books and journals, only hands you books published by the library itself. If you ask in a language other than English, the librarian might have even fewer local books to offer. In this paper, the AI search systems act like that librarian, favoring their own company platforms and varying their sources based on language and country.
People relying on AI-powered search for health advice may unknowingly be directed to content from the search company itself rather than independent medical sources. This matters most in countries with less local health content, where the problem is worse. The language you use also dramatically changes which sources you see, affecting millions who search in non-English languages.
The abstract doesn't say explicitly, but the study only covers health queries on two platforms in 12 countries and 4 languages, and does not assess the accuracy of the summaries or explore reasons for the patterns.
Ask anything about this paper. Answers come from its abstract, and say so when the abstract doesn't cover your question.
Who Anchors AI Overviews in Health? Baidu, Google, and the Geography of Authority — Mingyue Zha, Ho-Chun Herbert Chang
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.