Logic & Philosophy of Science Colloquium

Simon Huttegger

University of Salzburg; UCI Visiting Student

"Efficient Social Contracts and Population Growth"

Abstract: Social contracts are sets of conventions that allow members of human or non-human societies to coordinate their actions. Those conventions might be more or less efficient, where efficiency means absence of waste. Standard evolutionary game theoretic models, such as the replicator dynamics, do not offer good explanations of the evolution of cooperative behavior in games where there is an efficient but risky, and a less risky but inefficient equilibrium. A simple game of this kind is the Stag Hunt game. We will investigate the evolution of cooperative behavior in the Stag Hunt game in finite populations with the potential to grow. In order to do this, we employ a stochastic model which is connected to the replicator dynamics by some limiting results. However, due to the higher growth rate of cooperative individuals and due to drift phenomena that can occur while the population is small, in the stochastic model an efficient population of cooperators is more likely to emerge from a not entirely cooperating initial population than in the replicator dynamics. By introducing environmental pressure we find even more cooperating societies among the populations that do not go extinct during the initial periods of play.

Friday, May 20, 2005
SST 777
3 pm

Refreshments will be served