I consider transactions involving asymmetric prisoners`dilemmas between pairs of players selected chosen from two large populations. Games are played repeatedly, but information about cheating is not adequate to sustain cooperation, and there is no official legal system of contract enforcement....

Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy while others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic...