Abstract
In this paper we argue that natural resource conservation is jeopardised by the ability of users to resort to violence to appropriate resources when they become scarce. We provide evidence from a lab experiment that participants interacting in a dynamic game of common pool resource extraction reduce their cooperation on efficient levels of resource extraction when given the possibility to appropriate the resource at some cost, i.e. through conflict. Theoretically, cooperation is achievable via the threat of punishment strategies, which stop being subgame perfect in the presence of conflict. Accordingly we argue that the observed reduction of cooperation in the game's early stages in the lab is a consequence of participants (correctly) anticipating the use of appropriation when resources become scarce.