The aim of this paper is to present Arrow's theorem and more generally the common framework of many results which can be called "Arrovian theorems". One begins by recalling the Condorcet majority rules, and why they fail: the "effet Condorcet". These rules are examples of preference aggregation...

Two approaches to equilibrium selection are contrasted in the context of an investment-opportunism-retaliation (IOR) game. In this game, a valuable (efficient) investment may be forgone in the face of opportunistic behavior, however, players who are victims of opportunism may retaliate to the...