Under what conditions can class divisions characterized by high levels of inequality be designated evolutionary universals, using Talcott Parsons's term to refer to social arrangements which have emerged independently and persisted in a wide variety of environments? To explore this question, I represent economic institutions as bargaining conventions and then in order to better capture the historically observed processes of institutional evolution I extend recent models in stochastic evolutionary game theory in four ways: i) non-best response (idiosyncratic) play is modeled as intentional rather than accidental, ii) non best response play is coordinated through a process of collective action, iii) substantial rates of non-best response play are introduced, and iv) the sub-populations making up the classes may be of different sizes. In this model, contrary to the conventional formulation, highly unequal and economically inefficient institutions may be stochastically stable states in the implied dynamical system, while more egalitarian institutions may prove ephemeral.
