Abstract

We study robust equilibria in tournaments, where agents endowed with power form coalitions, and the coalition formed with the highest power prevails. We introduce the No-Threat Equilibrium (NTE), a stable partition where if a coalition deviates, then a new coalition could counter by forming an even stronger coalition. The NTE exists for any power function and preferences if and only if the set of feasible coalitions is a ‘Helly’ family.

In contrast, the core is a partition in which no group of agents can profitably deviate by forming a feasible coalition, assuming that other agents do not react to such a deviation. The core is not empty for any power function and preferences if and only if the set of feasible coalitions has a ‘hierarchical-structure’.

The paper also adapts and characterizes other stability concepts to tournaments, including the α-core, β-core, farsighted core and bargaining set.

研究成果：Robust equilibria in tournaments

发表期刊：GAMES AND ECONOMIC BEHAVIOR

论文链接：

https://www.sciencedirect.com/science/article/pii/S0899825623001318