A Dual Description of the Class of Games with a Population Monotonic Allocation Scheme

A vector of balanced weights infers an inequality that games with a nonempty core obey.This paper gives a generalization of the notion `vector of balanced weights'.Herewith it provides necessary and sufficient conditions to determine whether a TU-game has a population monotonic allocation scheme or not. Furthermore it shows that every 4-person integer valued game with a population monotonic allocation scheme has an integer valued population monotonic allocation scheme and it gives an example of a 7-person integer valued game that has only non-integer valued population monotonic allocation schemes.