David Chandler Thomas is a Ph.D. student in George Mason University's economics program. I had highly recommended him to the program after having been his thesis advisor. (San Jose State University, where he earned his Masters' degree had asked me to do so.)
David reported the following story.
Conversation with one of my Environmental Economics students at the final exam regarding the two large plates of cookies I made for the students.
Student: Are these cookies a common pool resource?
Me: I suppose.
Student: In that case there is about to be a tragedy of the commons.
Me: This class has certain social norms.
Student: I will not see them again so I don't care about social norms.
Me: You forget that I have not graded your exam yet and I assure you that sequential game theory will apply.