Binary Operations for the Lattice Structure in a Many-to-Many MatchingModel

The lattice structure of the set of stable matchings in many-to-many matching model is well known in literature.If preferences of the agents are substitutable,this result can be obtained by fixed-point methods,for that purpose an algorithm for finding a fixed-point matching is defined.Since the fixed-point set equals the set of stable matchings,the latter has a lattice structure too.In this paper,we consider a many-to-many matching market where the preferences of firms satisfy substitutability and the law of aggregate demand,and workers have responsive preferences.In this many-to-many matching market,we explicitly compute for any pair of stable matchings the least upper bound and the greatest lower bound,without using fixed-point methods.