Echo chambers: Choosing interlocutors and messages

We provide a rational explanation for the formation of echo chambers through a novel communication game in which individuals strategically choose both whom to communicate with and what to convey. Our key insight highlights a fundamental trade-off: individuals must balance the goal of gathering truthful information against the desire to influence others when selecting communication partners. This trade-off plays a critical role in the emergence of echo chambers. Our theory and experiment demonstrate that people acquire more accurate information from those of the same type, but exert greater influence over those of a different type. Experimental results show that individuals tend to engage with like-minded counterparts unless the incentive to persuade others is exceptionally strong. These findings offer valuable insights into how information and influence shape social networks and contribute to the persistence of ideological segmentation.