The Tracing Procedure in A Population Game Model

The paper provides an evolutionary game theoretic reinterpretation of Harsanyi's (1975) tracing procedure and introduces a new solution concept for a population game model. In our population game theoretic interpretation players' common prior is the initial population state, and the tatonnement process is not a mental process but a gradual change of the population state. The population dynamic guarantess convergence to a Nash equilibrium, since its limit point is the same as the Nash equilibrium in the original tracing procedure. We also use the population tracing procedure repeatedly to define a refinement of Nash equilibria and call the limit set under the iterated population tracing procedure a 'population stable set' (PSS below). It is shown that a PSS always exists and that Swinkels' (1992) equilibrium evolutionarily stable set is a PSS.