Detecting bias in algorithms used to disseminate information in social networks

Authors: Vedran Sekara, Ivan Dotu, Manuel Cebrian, Esteban Moro, and Manuel Garcia−Herranz
Publication: PNAS Nexus, 2025, 4, pgaf291 [Journal | ArXiv]

Abstract: Social connections are conduits through which individuals communicate, information propagates, and diseases spread. Identifying individuals who are more likely to adopt ideas and spread them is essential in order to develop effective information campaigns, maximize the reach of resources, and fight epidemics. Consequently, a lot of work has focused on identifying influencers in social networks with various influence maximization algorithms being proposed. Based on extensive computer simulations on synthetic and 10 diverse real-world social networks we show that seeding information in social networks using state-of-the-art influence maximization methods creates information gaps. Our results show that these algorithms select influencers who do not disseminate information equitably, threatening to create an increasingly unequal society. To overcome this issue, we devise a multiobjective algorithm which both maximizes influence and information equity. Our results demonstrate it is possible to reduce vulnerability at a relatively low trade-off with respect to spread. This highlights that in our search for maximizing the spread of information we do not need to compromise on information equality.

Media

• How Algorithmic outreach lead to information inequality, Health Medicine Network
• Algorithmic Outreach Drives Growing Information Inequality, Scienmag