Imagine the following thought-experiment: suppose you are in my “Advanced Topics in Law” class and further suppose that I, your instructor, have posted the following “extra credit challenge” to the entire class:
You can each earn some extra credit on your term paper. You get to choose whether you want 2 points added to your grade, or 6 points. But there’s a catch: if more than 10% of the class selects 6 points, then no one gets any points. All selections are anonymous, and the course grades are not curved.
So, do you choose 2 points or go for 6?
The Logic of Social Dilemmas
This ingenious example illustrates the logic of a strategic situation known as a “social dilemma.” Often, in strategic situations like these, there’s a public resource–an open-access area or “commons”–that people can freely use to benefit themselves. In my classroom example it’s points, but in the real world the public resource could be the air, water supplies, fish stocks, etc.
Also, notice that the logic of a social dilemma is the same logic as that of the Prisoner’s Dilemma–but with more than two players. If everyone limits their personal use of the public resource, the group will thrive, but if too many people behave selfishly (trying to maximize their own personal outcomes), then the group eventually suffers because everyone is left with nothing as the public resource is depleted.
Stated formally, a “social dilemma” is a multi-player Prisoner’s Dilemma, that is, a dilemma involving n number of players, when n > 2. In addition, notice that the number of players does not alter the strategic aspect of the situation because, broadly speaking, it feels good to be cooperative both from a strategic and an ethical perspective. After all, if every student chose 2 points, everyone would get the extra credit, thus making it a rational choice. Also, it’s the communal choice, based on an ethical imperative to do what’s best for everyone in the group.
The strategic problem, however, is that many students might choose the seemingly selfish option. Why? Perhaps to increase their own grades, or perhaps because they fear that they will be taken advantage of. In short, no one wants to be the chump who chooses fewer points when they could have had more. Furthermore, from a purely selfish perspective, the ideal scenario would be if everyone else was cooperative but you were selfish, thereby maximizing your reward while maintaining the overall health of the group. But it rarely works out that way, and people often find themselves in deadlocks of mistrust with others in their group.
I will discuss a real-world example of a social dilemma, one from the world of business (commercial aviation), in the next day or two …
 As the screenshot pictured above shows, this is not a make-believe example. Some professors have actually given this “extra credit challenge” to their students. See, e.g., Dylan Selterman, “Why I give my students a ‘tragedy of the commons’ extra credit challenge,” The Washington Post (July 20, 2015).