Antoine Pietri

Guillaume Cheikbossian (CEE-M, Univ Montpellier) et Antoine Pietri (CEE-M, Univ Montpellier)

Abstract : This project aims at understanding whether individuals are affected by evolutionary forces when making decisions in a two-player Tullock contest. Indeed, the experimental literature shows that contestants almost systematically invest more effort in the contest than predicted by the Nash equilibrium. One possible explanation is that there are evolutionary forces that induce people to beat the others, resulting in overbidding compared to the Nash prediction. However, testing the predictions of evolutionary game theory requires a very long-time horizon, which is very difficult to implement in the lab. Therefore, we propose an experimental design that — we believe — can help us to understand if evolutionary forces impact participants’ decisions. To do so, we start from the « evolutionary » vision in which an equilibrium is evolutionary stable if the introduction of a new strategy (called mutant strategy) into a finite population does not change the equilibrium of the game. Thus, we expose participants of a traditional two-player contest experiment to mutant, i.e. some of them  have their decision dictated by the experimenter. Observing the reaction of participants to the invasion of « mutants » allows us to understand how evolutionary forces influence the decision-making process of individuals. Our results — prudently —  point that the concept of evolutionary stable strategy is not a potential justification for the fact that subjects in a two-player contest experiment tend to invest too much effort in the contest, compared to the Nash equilibrium prediction. We believe that this non-significant result adds insight to the literature.