“Computing power indices for weighted voting games via dynamic programming” has been co-authored by Staudacher, Stach, et al. and is aimed at providing efficient algorithms for computing various power indices. These algorithms – soon expected also as an R-package – allow one to model weighted voting situations with hundreds of voters.
The paper titled Brexit and Power in the Council of the European Union discusses the impact of Brexit on voting in the Council of the European Union. There is a remarkably sharp relation between population size and the change in power: Brexit increases the largest members’ powers while decreasing the smallest ones’ powers.
The paper is freely downloadable.
In the paper titled The equivalence of the minimal dominant set and the myopic stable set for coalition function form games (co-authored with P. Jean-Jacques Herings) published in Games and Economic Behavior, the equivalence of two dynamic cooperative game theoretic concepts, the minimal dominant set and the myopic stable set is studied and the modifications needed for equivalence are presented.
The paper is freely downloadable from the publisher’s site.
The paper “Scarce and directly beneficial reputations support cooperation” by Szabolcs Számadó (joint with Flóra Samu and Károly Takács) has been published recently in Scientific Reports.
A human solution to the problem of cooperation is the maintenance of informal reputation hierarchies. Reputational information contributes to cooperation by providing guidelines about previous group-beneficial or free-rider behaviour in social dilemma interactions. How reputation information could be credible, however, remains a puzzle. We test two potential safeguards to ensure credibility: (i) reputation is a scarce resource and (ii) it is not earned for direct benefits. We test these solutions in a laboratory experiment in which participants played two-person Prisoner’s Dilemma games without partner selection, could observe some other interactions, and could communicate reputational information about possible opponents to each other. Reputational information clearly influenced cooperation decisions. Although cooperation was not sustained at a high level in any of the conditions, the possibility of exchanging third-party information was able to temporarily increase the level of strategic cooperation when reputation was a scarce resource and reputational scores were directly translated into monetary benefits. We found that competition for monetary rewards or unrestricted non-monetary reputational rewards helped the reputation system to be informative. Finally, we found that high reputational scores are reinforced further as they are rewarded with positive messages, and positive gossip was leading to higher reputations.
The paper “Competitive equilibria in Shapley–Scarf markets with couples” by Fatma Aslan (joint with Jean Lainé) has been published recently in Journal of Mathematical Economics.
Regulated third party access (TPA) obliges the owner of an infrastructure, such as a natural gas pipeline to make it available for any user for a fee. If we want to model the European pipeline network with TPA, we must consider externalities. Kóczy’s paper titled “Modeling transfer profits as externalities in a cooperative game-theoretic model of natural gas networks” (joint with Dávid Csercsik, Franz Hubert and Balázs Sziklai) recently published in Energy Economics uses a simple partition function form game to model it. The paper is downloadable for free for 50 days.