The tragedy of the commons is an all too familiar problem. The nature of public goods games almost seems to ensure that the good will eventually get depleted or otherwise rendered useless. Evolutionary game theory can be used to project an increasing rate of destruction if we consider the two types of people in a given population, contributors to the resource and free riders. In small enough concentrations, the contributors positive benefit may counteract the negative of the free riders. However, the free riders extract more use as a result of not having the cost of maintenance. This will give them an advantage, which would lead to the production of more free riders and maybe even the conversion of some contributors to free riders, upon seeing they are fighting a losing battle. It would seem the Nash equilibrium to be reached would be everyone exploiting until the resource is depleted.
The challenge of society is to stigmatize free riding and glorify contribution in various ways to achieve a sustainable existence. However, this is operating under the assumption of two groups trying to get use out of a resource. A study published in the Journal of Theoretical Biology (http://www.sciencedirect.com/science/article/pii/S0022519311001639) explores what would happen if a third population is introduced. Termed “Jokers”, after the Batman villain and with particular reference to The Dark Night film, this population is destructive, but without actually making use of the resource in anyway. The destruction in and of itself is enough utility. Certainly there exist these types of people in the real world, but I think the notion could also be applied to natural disasters, unforeseen man-made disasters and unintended destruction as a result of the a presumed separate action.
The addition of these destructive actors actually serves to increase the evolutionary viability of the cooperative population. This is because the Jokers don’t make use of the public good as the free riders do. Therefore in a population of all 3 a cycle is created. At first the free rider(F) population grows larger off of the benefit generated by the cooperators(C). Eventually, the C population is diminished to a level where it can’t sustain itself and the Fs. The F population then shrinks as the Jokers destroy the dwindling benefit generated by C. However, as a result of the shrunken F population, the C population can now make substantial gains since they will enjoy an almost entirely non-leeched pool of benefits. The C population will grow faster here than Jokers can since Jokers enjoy no benefits from the public goods. Being cyclical this process continues indefinitely. It becomes unstable if Jokers are too destructive (leading to an all joker population) or if the free riders are somehow eliminated (leading to mostly C with a manageable joker subpopulation.
This supports the strength of a common enemy principle in which temporary large cooperative gains can be made thanks to the rallying force against a purely destructive enemy. You can call it the Independence day principle or the Watchmen principle depending on how geeky you want to get. The conclusion from all this seems to be that in addition to incentivizing cooperation and shaming free riding in traditional manners, we can promote cooperation through the use of fictional or real disasters. I’d say this what seems likely to occur as global climate change produces increasingly more destructive weather, but it doesn’t seem even the recent New York hurricane did the trick. The tipping point may only come once the Joker group has become too powerful. I also think this might have interesting applications in political revolution prediction and modeling, but thats for another day.