We study informal insurance within communities, explicitly recognizing the possibility that subgroups of individuals may destabilize insurance arrangements among the larger group. We therefore consider self-enforcing risk-sharing agreements that are robust not only to single-person deviations...

The classical Fisher equation asserts that in a nonstochastic economy, the inflation rate must equal the difference between the nominal and real interest rates. We extend this equation to a representative agent economy with real uncertainty in which the central bank sets the nominal rate of...

Dynamic decision-making without commitment is usually modelled as a game between the current and future selves of the decision maker. It has been observed that if the time-horizon is infinite, then such games may have multiple subgame-perfect equilibrium solutions. We provide a sufficient...

During the last three decades the ascent of behavioral economics clearly helped to bring down artificial disciplinary boundaries between psychology and economics. Noting that behavioral economics seems still under the spell of the rational choice tradition and, indirectly, of behaviorism we...

We present two new notions of evolutionary stability, the trulyevolutionarily stable state (TESS) and the generalized evolutionarilystable equilibrium (GESE). The GESE generalizes the evolutionar-ily stable equilibrium (ESE) of Joosten [1996]. An ESE attracts allnearby trajectories...

Agents interacting on a body of water choose between technologiesto catch …sh. One is harmless to the resource, as it allows full recovery;the other yields high immediate catches, but low(er) future catches.Strategic interaction in one ‘objective’resource game may induceseveral ‘subjective’...

We introduce a stochastic game in which transition probabilitiesdepend on the history of the play, i.e., the players’past action choices.To solve this new type of game under the limiting average reward crite-rion, we determine the set of jointly-convergent pure-strategy rewardswhich can be...

A well—known result from the theory of finitely repeated games statesthat if the stage game has a unique equilibrium, then there is a uniquesubgame perfect equilibrium in the finitely repeated game in which theequilibrium of the stage game is being played in every period. Here Ishow that this...

It is well known that the rock-paper-scissors game has no pure saddle point. Weshow that this holds more generally: A symmetric two-player zero-sum game hasa pure saddle point if and only if it is not a generalized rock-paper-scissors game.Moreover, we show that every finite symmetric...

We show that for many classes of symmetric two-player games, the simple decision rule \imitate-the-best" can hardly be beaten by any other decision rule. Weprovide necessary and sufficient conditions for imitation to be unbeatable and showthat it can only be beaten by much in games that are of...