Tarik Tazdaït

HOW TO PLAY GAMES? NASH VERSUS BERGE BEHAVIOUR RULES

Social interactions regularly lead to mutually beneficial transactions that are sometimes puzzling. The prisoner’s dilemma and the chicken and trust games prove to be less perplexing than Nash equilibrium predicts. Moral preferences seem to complement self-oriented motivations and their relative predominance in games is found to vary according to the individuals, their environment, and the game. This paper examines the appropriateness of Berge equilibrium to study several 2×2 game situations, notably cooperative games where mutual support yields socially better outcomes. We consider the Berge behavior rule complementarily to Nash: individuals play one behavior rule or another, depending on the game situation. We then define non-cooperative Berge equilibrium, discuss what it means to play in this fashion, and argue why individuals may choose to do so. Finally, we discuss the relationship between Nash and Berge notions and analyze the rationale of individuals playing in a situational perspective.

Bargaining over a climate deal: deadline and delay

Assuming that a North-South transfer is the key to effective climate cooperation, we ask when and how much the North should offer to the South in return for a commitment to reduce deforestation and forest degradation. In light of the risk of irreversible damage over time, we examine a negotiation with a deadline. In this case, the North threatens the South over a negotiation dead-end in case an agreement is not reached rapidly. We assess the conditions for an agreement to be immediate or delayed, and discuss those situations likely to result in negotiation failure. Despite the risk of irreversible damage over time, we show that cooperation is likely to be delayed and we identify situations wherein the North and South do not reach an agreement within the deadline. Although Pareto-improving, cooperation may collapse because of inefficiencies related to incomplete information. What’s more, we show that in negotiations with a deadline, uncertainty about the benefits deriving from cooperation and the irreversibility of the damage that will be caused if cooperation is delayed are the two key components affecting choice.

1. Les enjeux du paradoxe du vote

Les mauvais politiciens sont elus par les bons citoyens qui ne votent pas.George Jean Nathan Presentation Les sens donnes a la participation electorale Les definitions generalement offertes de la democratie insistent souvent sur le caractere central de la participation des citoyens aux elections, au point de faire du vote la cle de voute des regimes democratiques. Nombreux sont les auteurs a defendre ce point de vue, a l’image de Curtis Gans (1978, p. 54) pour qui «xa0la legitimite de la democr...

2. La minimisation du regret maximal

Je n’ai jamais vote pour quelqu’un, j’ai toujours vote contre [quelqu’un].W. C. Fields En cherchant a resoudre le «xa0paradoxe du votexa0», John Ferejohn et Morris Fiorina (1974) ont etabli une distinction interessante entre leur approche et celle d’Anthony Downs (1957). Rappelons que la decision de vote dans le modele de Downs correspond a une decision d’investissementxa0: face a un benefice futur incertain (PB), l’individu se doit de supporter un cout au montant certain (egal a C). Ces auteurs co...