📝 SummarXiv

Abstract

We study rationally inattentive echo chambers, where players allocate limited attention to biased primary sources and to other players as secondary sources to acquire information about an uncertain state. The resulting Poisson attention network stochastically transmits information from primary sources either directly or indirectly through others. We give conditions for echo-chamber equilibria, in which players restrict attention to their own-biased source and same-type peers. We characterize equilibrium attention networks, developing tools for comparative statics. Our results explain why modern information environments foster echo chambers, how small heterogeneity in attention capacities can magnify into large disparities in allocations, and why regulatory interventions such as altering user visibility on social media or mandating exposure to opposing views may backfire with unintended consequences.