Where the earth is flat and 9/11 is an inside job: A comparative algorithm audit of conspiratorial information in web search results

Web search engines are important online information intermediaries that are frequently used and highly trusted by the public despite multiple evidence of their outputs being subjected to inaccuracies and biases. One form of such inaccuracy, which so far received little scholarly attention, is the presence of conspiratorial information, namely pages promoting conspiracy theories. We address this gap by conducting a comparative algorithm audit to examine the distribution of conspiratorial information in search results across five search engines: Google, Bing, DuckDuckGo, Yahoo and Yandex. Using a virtual agent-based infrastructure, we systematically collect search outputs for six conspiracy theory-related queries (“flat earth”, “new world order”, “qanon”, “9/11”, “illuminati”, “george soros”) across three locations (two in the US and one in the UK) and two waves (March and May 2021). We find that all search engines except Google consistently displayed conspiracy-promoting results and returned links to conspiracy-dedicated websites, with variations across queries. Most conspiracy-promoting results came from social media and conspiracy-dedicated websites while conspiracy-debunking information was shared by scientific websites and legacy media. These observations are consistent across different locations and time periods highlighting the possibility that some engines systematically prioritize conspiracy-promoting content.