Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2003.Includes bibliographical references.Chapter 1 analyzes how pre-play communication and evolution together do or do not lead to socially efficient equilibria in 2 x 2 symmetric coordination games. In our evolutionary dynamics, there are committed players who can choose only one particular action of the base game, as well as those players who can choose message contingent actions, and the evolution in the choice of message is faster than the evolution in actions. We show the Pareto efficient equilibria are selected if and only if the base game satisfies the self-signalling condition, which means that a player has an incentive to convince the opponent that he is go...