Game theoretic modeling of helping behavior in emergency evacuations with committed volunteers

We study how the presence of committed volunteers influences on the collective helping behavior in emergency evacuation scenario. In this study, the committed volunteers do not change their decision to help the injured persons, implying that other evacuees may adapt the helping behavior through strategic interactions. An evolutionary game theoretic model is developed and then coupled with pedestrian movement model to examine the collective helping behavior in evacuations. By systematically controlling the number of committed volunteers and payoff parameters, we have characterized and summarized various collective helping behaviors in phase diagrams. From our numerical simulations, we have observed that the existence of committed volunteers can promote the cooperation but adding additional committed volunteers is effective only above a certain number of committed volunteers. This study also highlights that the evolution of collective helping behavior is strongly affected by the evacuation process.