"The enemy of my enemy is my friend." This common adage, which seems to be adhered to in social interactions (e.g. high school cliques or work relationships) as well as in political alliances within countries and between countries, describes the ability of groups or people to work together when...

This paper presents a game-theoretic rationale for the beneficial effect of a common enemy on cooperation. In a defence game against a common natural threat, the value of the public good of defence is equal to the sum of the players’ defensive efforts. The game therefore takes the form of...

The set of equilibrium networks in the two-way flow model of network formation (Bala and Goyal, 2000) is very sensitive to the introduction of decay. Even if decay is small enough so that equilibrium networks are minimal, the set of equilibrium architectures becomes much richer, especially when...

This paper shows that Rubinstein’s results on the two-player electronic mail game do not extend to the N-player electronic mail game.

This paper distinguishes between two scenarios for the expert-client encounter. In the cure scenario, the client does not know whether a loss can be recovered. In the prevention scenario, the client faces a threat but does not know whether this threat is real enough to justify preventive action....