We provide two new characterizations of exact games. First, a game is exact if and only if it is exactly balanced; and second, a game is exact if and only if it is totally balanced and overbalanced. The condition of exact balancedness is identical to the one of balancedness, except that one of the...

We modify the story behind the Shapley-Shubik power index and apply it to a legislative body. The resulting proportional index may be trivial, but is free from the paradoxical behaviour observable with standard power indices. The widespread use of this index may in fact be the reason for these...

The measurement and the allocation of risk are fundamental problems of portfolio management. Coherent measures of risk provide an axiomatic approach to the former problem. In an environment given by a coherent measure of risk and the various portfolios' realization vectors, risk allocation games...

While they use the language of game theory known measures of a priory voting power are hardly more than statistical expectations assuming voters behave randomly. Focusing on normalised indices we show that rational players would behave differently from the indices predictions and propose a model...

For each outcome (i.e. a payoff vector augmented with a coalition structure) of a TU-game with a non-empty coalition structure core there exists a finite sequence of successively dominating outcomes that terminates in the coalition structure core. In order to obtain this result a restrictive...

A set of outcomes for a TU-game in characteristic function form is dominant if it is, with respect to an outsider-independent dominance relation, accessible (or admissible)and closed. This outsider-independent dominance relation is restrictive in the sense that a deviating coalition cannot...

In the model of Funaki and Yamato (1999) the tragedy of the commons can be avoided with pessimistic players, while this does not hold for optimistic players. We propose a new core concept to overcome this puzzle and provide numerical simulations of simple games where the conclusions coincide or...

The sequential coalition formation model of Bloch (1996) to solve cooperative games with externalities exhibits some anomalies when related to classical concepts. We elaborate on these problems, define a modification of Bloch's model and show that its order-independent equilibria coincide with...

Egy központi felvételi rendszer feladata a jelentkezők és az iskolák, vagy szakok párosítása. Ez a párosítás többféleképpen is történhet, azonban a gyakran igen különböző felvételi rendszerek is leírhatók néhány alapelv mentén. Ilyen alapelvként fogalmazható meg, hogy...