We investigate the computational complexity of a decision problem in hedonic coalition formation games. We prove that core stability in additive hedonic games is complete for the second level of the polynomial hierarchy.

The Hirsch-index is a well-known index for measuring and comparing the output of scientific researchers. The main contribution of this article is an axiomatic characterization of the Hirsch-index in terms of three natural axioms. Furthermore, two other scientific impact indices (called the...

We show that the following problem is NP-hard, and hence computationally intractable: "Given a vector y that Lorenz-dominates a vector x, what is the smallest number of Muirhead-Dalton transfers that transform x into y?"

A recent paper by Aleskerov et al. [Aleskerov, F., Yakuba, V., Yuzbashev, D., 2007. A 'threshold aggregation' of three-graded rankings. Mathematical Social Sciences 53, 106-110] characterizes so-called threshold aggregation rules of three-graded rankings in terms of four axioms Anonymity,...