Noisy contagion without mutation

In a local interaction game agents play an identical stage game against the ir neighbours over time. For nearest neighbour interaction, it is establish ed that, starting from a random initial configuration in which each agent h as a positive probability of playing the risk dominant strategy, a sufficie ntly large population coordinates in the long-run on the risk dominant equi librium almost surely. Our result improves on Blume (1995), Ellison (2000), and Morris (2000) by showing that the risk dominant equilibrium spreads to the entire population in a two dimensional lattice and without the help of mutation, as long as there is some randomness in the initial configuration .