The Cost of the Game: A Taxonomy of Social Interactions

This paper considers the role of reciprocity rules in various strategic settings. After distinguishing four typical categories of social interaction, the paper examines three forms of reciprocity constraints. An ideal rule of perfect incentive alignment (structural reciprocity) serves as a benchmark for the analysis of a golden rule of reciprocity, characterized by a mechanical linking of one player's strategy to that of the other player; and a silver rule of stochastic reciprocity, characterized by a probabilistic symmetry in the relationship between the players.