Psychological game theory can provide a rational choice explanation of framing effects; frames influence beliefs, and beliefs influence motivations. We explain this point theoretically, and explore its empirical relevance experimentally. In a 2×2-factorial framing design of one-shot public good...

Substantial evidence has accumulated in recent empirical works on the limited ability of the Nash equilibrium to rationalize observed behavior in many classes of games played by experimental subjects. This realization has led to several attempts aimed at finding tractable equilibrium concepts...

We examine settings - such as litigation, labor relations, or arming and war - in which players first make non-contractible up-front investments to improve their bargaining position and gain advantage for possible future conflict. Bargaining is efficient ex post, but we show that a player may...

This paper surveys the literature on group selection. I describe the early contributions and the group selection controversy. I also describe the main approaches to group selection in the recent literature; fixation, assortative group formation, and reproductive externalities. -- Altruism ; spite...