Impact of AI Search Summaries on Website Traffic: Evidence from Google AI Overviews and Wikipedia
Abstract
Search engines increasingly display AI-generated answers above organic links, potentially displacing traffic to upstream publishers. We estimate the impact of Google’s AI Overviews (AIO) on Wikipedia’s search traffic using AIO’s staggered geographic rollout and Wikipedia’s multilingual structure. Our difference-in-differences design compares monthly external-search referrals to English Wikipedia articles with referrals to the same articles in German and French, and finds that default AIO availability reduced English search traffic by 5.45\% and 4.82\% , respectively. Our results suggest that answer-producing digital intermediaries can materially reallocate attention away from informational publishers, with implications for content monetization, search platform design, and policy.