Groupe d’études et de recherche en analyse des décisions

Evolutionarily Stable Strategies

Ross Cressman Wilfrid Laurier University, Canada

The concept of an evolutionarily stable strategy (ESS) was introduced some thirty years ago by John Maynard Smith to predict the behavior of individuals in a biological population. The ESS has since become the cornerstone of evolutionary game theory, a theory that connects static solutions generalizing the Nash equilibrium (NE) from classical game theory with dynamic stability of behavioral evolution. The talk gives an overview of the development of evolutionary game theory from its initial use by biologists in the 1970s/80s and by economists in the 90s as an equilibrium selection technique to its current applications in many disciplines. ESS theory will be summarized for symmetric games (such as normal form (matrix) games, single-species population games, extensive form games) and illustrated through examples. Extensions to non-symmetric games will also be discussed. If time permits, the latter part of the talk will be based on my recent research that generalizes the theory and methods to games with continuous strategy spaces.