Online Exploration When Search Topic and Popularity Ranking Are Decoupled: Insights on Echo Chambers

35 Pages Posted: 14 Aug 2017

See all articles by Sagit Bar-Gill

Sagit Bar-Gill

Massachusetts Institute of Technology (MIT)

Neil Gandal

Berglas School of Economics, Tel Aviv University; Centre for Economic Policy Research (CEPR)

Date Written: August 5, 2017


Personalized search algorithms produce results that are both topically relevant and ranked by their general popularity and individual fit to users’ previous searches and choices. New choices from such tailored lists feed back into the algorithms, over time creating content echo chambers, where content exposure is increasingly biased toward users’ and their friends’ interests and views. We create an online search environment for TED Talks, where topic and popularity are separately controlled, and study the relationship between users’ characteristics and their reliance on own interests vs. crowd-based popularity sorting in content exploration. In topic-based searches, we randomly block/show popularity information to examine its impact on the tendency to explore. We find that high levels of sociability, previous experience with similar content, and a younger age are associated with an increased susceptibility to echo chambers, represented by little to no exploration and popularity sorting prior to content choice. Opinion leaders may alleviate echo chambers in their social circles as they conduct more topic-based exploration and exhibit lower popularity reliance. Showing popularity information increases opinion leaders’ popularity sorting, but does not impact non-leaders’ exploration. Our findings identify users’ echo chamber risk factors, and suggest that reducing the salience of popularity information may contribute to more balanced content exposure facilitated by opinion leaders.

Keywords: Content Exploration, Online Search, Online Content Choice, Decision Making, Opinion Leadership, Echo Chamber, Online Behavior

Suggested Citation

Bar-Gill, Sagit and Gandal, Neil, Online Exploration When Search Topic and Popularity Ranking Are Decoupled: Insights on Echo Chambers (August 5, 2017). Available at SSRN: or

Sagit Bar-Gill (Contact Author)

Massachusetts Institute of Technology (MIT) ( email )

77 Massachusetts Avenue
50 Memorial Drive
Cambridge, MA 02139-4307
United States

Neil Gandal

Berglas School of Economics, Tel Aviv University ( email )

Tel Aviv University
Tel Aviv 69978
+972 3 640 9907 (Phone)
+972 3 640 9908 (Fax)


Centre for Economic Policy Research (CEPR)

United Kingdom

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