Prisoners and the Prisoners’ Dilemma

Game theory and economics feature a famous scenario known as the “prisoners’ dilemma.” This is a situation in which if two people agree to cooperate with one another they’ll both be better off than if they both refuse to cooperate, but where each individual faces a strong incentive to refuse to cooperate. These issues arise all the time in life, but the classic illustration involved a plea-bargaining scenario. I thought of that because Michelle Alexander’s interesting op-ed on crashing the justice system is basically a nonmetaphorical prisoner’s dilemma and yet she doesn’t use the phrase.

The basic point is that the operation of the criminal justice system is only feasible because so few criminal defendants insist on a jury trial. If all defendants cooperated and insisted on a trial, it would in practice be necessary to let a huge number of them go free. Holding all the trials would overburden the system. The problem, in practice, is that as more and more defendants insist on going to trial, prosecutors will start offering increasingly generous plea bargains. It’s true that all defendants, as a class, would be better off if they all hung together and refused to bargain. But each individual defendant has a strong incentive to cut a deal. So the deals will be cut.