Abstract
<jats:p>News aggregators are among the primary gatekeepers of online news, shaping both consumption and production through the algorithms that rank stories and sources. We provide the first large-scale estimates of this algorithmic power using the example of Yandex News, Russia's largest aggregator. Combining archived front pages with 12.3 million published articles and outlet-level traffic data, we estimate that occupying the entire top-5 news block for a day raises an outlet's traffic by roughly 380,000 visitors. After a 2016 law made aggregators liable for cited content, Yandex halved its references to independent outlets, yet consumers did not penalize the manipulation: its referrals converted readers at the same rate, and its market share did not fall. Removed outlets shifted toward longer articles and stopped optimizing headlines for the algorithm, showing that aggregator algorithms shape not only news consumption but also production.</jats:p>