The Dilemma of Prisoners

Abstract

Stalin's Great Terror was one of history's most massive political purges. In its form, the Terror resembled a one-shot, n-person prisoner's dilemma game. Although the Terror could not have been sustained if prisoners cooperated, most prisoners defected against one another, as the model would predict. Yet the record of the Terror also demonstrated that in a mass purge there exists a wider strategy set than that of the prisoner's dilemma game. Using an illustrative case and a generalized model of purges, it is shown that if prisoners implicate their interrogators and play what is called a “transformation” strategy, they raise the cost to the authority of conducting the purge. In fact, the authority has no consistent best response to the transformation, and the purge should not be sustainable for long thereafter. The Great Terror was apparently limited by employment of this transformation. Limitations on the formation and use of such a strategy are also considered.