Eshwar Chandrasekharan

Eshwar Chandrasekharan is a computer scientist whose empirical research on content moderation and deplatforming has been built largely around data from Reddit. He completed his PhD at the Georgia Institute of Technology and is an assistant professor in the Siebel School of Computing and Data Science at the University of Illinois Urbana-Champaign, where he directs a social-computing research lab. His work sits at the intersection of human-computer interaction, machine learning, and online governance.

His most influential study is 'You Can't Stay Here: The Efficacy of Reddit's 2015 Ban Examined Through Hate Speech,' published in the Proceedings of the ACM on Human-Computer Interaction (CSCW) in 2017. Analysing more than 100 million Reddit posts and comments with custom hate-speech lexicons and a difference-in-differences design, the paper examined Reddit's 2015 ban of the subreddits r/fatpeoplehate and r/CoonTown. It found that hate-word usage among affected accounts dropped sharply relative to matched controls, that a substantial share of those users left Reddit entirely, and that communities absorbing migrating users did not inherit the banned groups' behaviour. The study is widely cited as foundational evidence that deplatforming can reduce on-platform harm.

Beyond that paper, Chandrasekharan has published on how moderation norms vary across thousands of subreddits and on the alignment between users and moderators in community governance. He also helped build Crossmod, an open-source machine-learning-backed moderation system that was tested in a large Reddit community, illustrating an applied dimension to his research.

His findings are frequently invoked in debates over whether platforms should ban toxic communities. Supporters cite the 2015 study as proof that removal works; critics note it measures on-platform behaviour rather than where displaced users ultimately go. Chandrasekharan is sometimes confused with the authors of the separate 2024 'The Great Ban' study, which was written by a team at the University of Pisa and IIT-CNR, not by him.