Excess payoff dynamics in games

We present the family of Excess Payoff Dynamics for normal-form games, where the growth of a strategy depends only on its current proportion and the excess payoff, i.e., the payoff advantage of the strategy over the average population payoff. Requiring dependence only on the own excess payoff and a natural sign-preserving condition, the class essentially reduces to aggregate monotonic dynamics, a functional generalization of the Replicator Dynamics. However, Excess Payoff Dynamics also include a different subclass which contains the Replicator Dynamics, the Brown-von Neumann-Nash Dynamics, and other interesting examples as, e.g., satisficing dynamics. We also clarify the relation to excess demand dynamics from microeconomics.