This paper proposes a learning-efficiency explanation of modular structure in language. An optimal grammar arises as the solution to the problem of learning a language from a minimal number of observations of instances of the use of the language. Agents face symmetry constraints that limit their...

This paper shows that the efficiency bound for communication equilibria identified by Goltsman et al. (2009) in the leading example of the Crawford–Sobel model can be obtained with strategy-correlated equilibria, thus preserving privacy vis-à-vis the mediator. More generally, all equilibrium...