Equilibrium Selection in Linguistic Games: Kial Ni (Ne) Parolas Esperanton?

Abstract

Taking our point of departure in an article by Selten and Pool and using the equilibrium selection theory developed by Harsanyi and Selten, we analyze the risk dominant equilibria of a language game. Into a model with two groups of people with different native ethnic languages, we introduce a further interethnic planned language, Esperanto, the learning of which is much easier than that of an ethnic language. Of the four strict and symmetric equilibria of the game-absence of international communication, use of Esperanto or one of the ethnic languages-two or three might coexist, depending on the values of the parameters of the model. Using the concept of risk dominance in order to select from those coexisting equilibria, we show that the introduction of Esperanto for some realistic parameter values is the unique solution. It is also an efficient solution, but all efficient solutions with Esperanto are not realised by such a risk dominant equilibrium. Finally, we explore in a speculative manner the possibility of analyzing the use of language with an evolutionary game.