Alex January 22, 2019 at 2:12 am 0:43:11 SC: If I understand it correctly, the Nash equilibrium is one where one person cannot unilaterally change to get a better outcome without hurting somebody else, but a Pareto improvement would be where, if we all change at once, we will all be better off, is that right? 0:43:29 DL: That’s exactly right, […] This is not “exactly right”. It has nothing to do with hurting other parties, that’s irrelevant. You are in a Nash Equilibrium when any change to your strategy you can enact will be counter to your interests (payoff function). In the prisoner dilemma game you defect because it doesn’t matter what your adversary does, you still benefit – either he defects too in which case you avoid a long sentence or he stays quiet in which case you get the lowest sentence. To do otherwise it to guarantee you cannot get the lowest sentence and open yourself to the possibility that you may get the highest.