Communication with Unknown Perspectives *

Consider a group of individuals with unobservable perspectives (subjective prior beliefs) about a sequence of states. In each period, each individual receives private information about the current state and forms an opinion (a posterior belief). She also chooses a target individual and observes the target’s opinion. This choice involves a trade-off between well-informed targets, whose signals are precise, and well-understood targets, whose perspectives are well known. Opinions are informative about the target’s perspective, so observed individuals become better understood over time. We identify a simple condition under which long-run behavior is history independent. When this fails, each individual restricts attention to a small set of experts and observes the most informed among these. A broad range of observational patterns can arise with positive probability, including opinion leadership and information segregation. In an application to areas of expertise, we show how these mechanisms generate own-field bias and large field dominance. ∗For their helpful suggestions, we thank Daron Acemoglu, Sanjeev Goyal, Navin Kartik, Joel Sobel, four anonymous referees, and participants at the 2014 Econometric Society Latin American Meetings, 2014 Workshop on Economic Theory (FGV), 2014 Time, Uncertainities and Strategies workshop (PSE), and seminars at ASU, University of Arizona, Bocconi, University of Chicago, University of Chile, Columbia, Harvard, MIT, and Northwestern. We also thank the Becker Friedman Institute at University of Chicago, the Institute for Advanced Study at Princeton, University of Pennsylvania, Princeton University, and Harvard University for hospitality and support. †Department of Economics, Barnard College, Columbia University and the Santa Fe Institute. ‡Department of Economics, MIT.