We give examples of strategic interaction which are beneficial for players who follow a "middle path" of balance between pure selfishness and pure altruism. JEL Classification: C70, C71, C72, C79.

We provide new, concise characterizations of the Banzhaf value on a …xed player set employing just the standard dummy player property and one of the collusion properties suggested by Haller (1994) and Malawski (2002). Within these characterizations, any of the collusion properties can be replaced by additivity and the quarrel property due to the latter author. Journal of Economic Literature Cla...

∗Institute of Mathematics; and Center for Rationality and Interactive Decision Theory; The Hebrew University of Jerusalem; Givat Ram; Jerusalem 91904; Israel. E-mail: [email protected] This research was in part supported by The Israel Science Foundation grant 382/98. J.E.L. Classification numbers. D70, D71, D63, C71

I survey the recent literature on the formation of networks. I provide definitions of network games, a number of examples of models from the literature, and discuss some of what is known about the (in)compatibility of overall societal welfare with individual incentives to form and sever links. JEL Classification Numbers: A14, C71, C72

We study minimum cost spanning tree problems and de…ne a cost sharing rule that satis…es many more properties than other rules in the literature. Furthermore, we provide an axiomatic characterization based on monotonicity properties. Keywords: Spanning tree. Cost allocation. Monotonicity. JEL Classi…cation Numbers: C71, D63, D7.

In interim economies with asymmetric information, we show that the coarse core of Wilson (1978) does not converge to price equilibrium allocations as the economy is replicated. This failure of core convergence is a basic consequence of asymmetric information and extends to any reasonable notion of either (interim) core or price equilibrium. JEL Classification: C71, D51

Allocation rules for cooperative games can be manipulated by coalitions merging into single players, or, conversely, players splitting into a number of smaller units. This paper collects some (im)possibility results on mergingand splitting-proofness of (core) allocation rules for cooperative games with side-payments. JEL classification: C71, D23, D71.

We analyze the ex ante incentive compatible core for replicated private information economies. We show that any allocation in the core when the economy is replicated sufficiently often is approximately Walrasian for the associated Arrow–Debreu economy.  2004 Elsevier Inc. All rights reserved. JEL classification: C7; C71; D5

We introduce a model of bargaining among groups, and characterize a family of solutions using a Consistency axiom and a few other invariance and monotonicity properties. For each solution in the family, there exists some constant α ≥ 0 such that the "bargaining power" of a group is proportional to cα, where c is the cardinality of the group. Subject classification: JEL C71, C78