The Politics of Personalized News Aggregation

We study how personalized news aggregation for rationally inattentive voters (NARI) affects policy polarization and public opinion. In a two-candidate electoral competition model, an attention-maximizing infomediary aggregates source data about candidates' valence into easy-to-digest news. Voters decide whether to consume news, trading off the expected gain from improved expressive voting against the attention cost. NARI generates policy polarization even if candidates are office-motivated. Personalized news aggregation makes extreme voters the disciplining entity of policy polarization, and the skewness of their signals is crucial for sustaining a high degree of policy polarization in equilibrium. Analysis of disciplining voters yields insights into the equilibrium and welfare consequences of regulating infomediaries.