The stable fixtures problem with payments.

We consider multiple partners matching games (G,b,w), where G is a graph with an integer vertex capacity function b and an edge weighting w. If G is bipartite, these games are called multiple partners assignment games. We give a polynomial-time algorithm that either finds that a given multiple partners matching game has no stable solution, or obtains a stable solution. We characterize the set of stable solutions of a multiple partners matching game in two different ways and show how this leads to simple proofs for a number of results of Sotomayor (1992, 1999, 2007) for multiple partners assignment games and to generalizations of some of these results to multiple partners matching games. We also perform a study on the core of multiple partners matching games. We prove that the problem of deciding if an allocation belongs to the core jumps from being polynomial-time solvable for b≤2 to NP-complete for b≡3