The paper presented in this Virtual Market Design Seminar studies learning via shared news. Each period agents receive the same quantity and quality of first-hand information and can share it with friends. Some friends (possibly few) share selectively, generating heterogeneous news diets across agents akin to echo chambers. Agents are aware of selective sharing and update beliefs by Bayes’ rule. Contrary to standard learning results, the authors show that beliefs can diverge in this environment leading to polarization. This requires that (i) agents hold misperceptions (even minor) about friends’ sharing and (ii) information quality is sufficiently low. Polarization can worsen when agents’ social connections expand. When the quantity of first-hand information becomes large, agents can hold opposite extreme beliefs resulting in severe polarization. Their results hold without media bias or fake news, so eliminating these is not sufficient to reduce polarization. When fake news is included, the authors show that it can lead to polarization but only through misperceived selective sharing. News aggregators can curb polarization caused by shared news.


Renee Bowen

UC Sand Diego, USA

If you would like to participate and to stay up to date about upcoming presentations, please join our mailing list. You will receive the Zoom link for each talk.

The seminar presentations are scheduled to last 60 minutes: 45 minutes of presentation and 15 minutes for both comments and questions.

We will experiment with various methods for questions: A moderator collects questions during the presentation. Speakers will be encouraged to pause every few slides to allow a gap for questions. The moderator will relay clarification questions or unmute selectively during the talk. Remaining questions will be collected and asked in the discussion period.

Just like with other initiated virtual seminars, these rules are subject to change as we gain experience with how to handle the seminar most efficiently.

The idea for this format was borrowed from the Chamberlain Seminar. Other online seminars can be found at the AEA website.

The Virtual Market Design Seminar is an open online alternative to seminars cancelled due to the COVID-19. Seminars will cover all fields from market design. The seminar presentations are scheduled to last 60 minutes, after 45 minutes of presentation, 15 minutes are for both comments and question.


26.04.2021 | 16:00 - 17:00 (CET)

Event Location