Influential Opinion Leaders

We present a two-stage coordination game in which early choices of experts with special interests are observed by followers who move in the second stage. We show that the equilibrium outcome is biased towards the experts' interests even though followers know the distribution of expert interests. Expert influence is fully decentralised in the sense that each individual expert has a negligible impact. The bias in favour of experts results from a social learning effect that is multiplied through a coordination motive. We apply our results to the onset of social movements and to the diffusion of products with network externalities.