The Cooperative Theory of Two Sided Matching Problems: A Re-examination of Some Results

We show that, given two matchings of which say the second is stable, if (a) no firm prefers the first matching to the second, and (b) no firm and the worker it is paired with under the second matching prefer each other to their respective assignments in the first matching, then no worker prefers the second matching to the first. This result is a strengthening of a result originally due to Knuth (1976). A theorem due to Roth and Sotomayor (1990), says that if the number of workers increases, then there is a non-empty subset of firms and the set of workers they are assigned to under the F – optimal stable matching, such that given any stable matching for the old two-sided matching problem and any stable matching for the new one, every firm in the set prefers the new matching to the old one and every worker in the set prefers the old matching to the new one. We provide a new proof of this result using mathematical induction. This result requires the use of a theorem due to Gale and Sotomayor (1985 a,b), which says that with more workers around, firms prefer the new optimal stable matchings to the corresponding ones of the old two-sided matching problem, while the opposite is true for workers. We provide an alternative proof of the Gale and Sotomayor theorem, based directly on the deferred acceptance procedure.Two-sided matching, Stable

Existence of Equilibrium in Discrete Market Games

In this paper we show that a feasible price allocation pair is a market equilibrium of a discrete market game if and only if it solves a linear programming problem. We use this result to obtain computable necessary and sufficient conditions for the existence of market equilibrium. We assume that the production functions of the profit maximizing agents are discrete concave.discrete concave, existence, market equilibrium, linear programming

Stable Matchings for the Room-mates Problem

We show that, given two matchings for a room-mates problem of which say the second is stable, and given a non-empty subset of agents S if (a) no agent in S prefers the first matching to the second, and (b) no agent in S and his room-mate in S under the second matching prefer each other to their respective room-mates in the first matching, then no room-mate of an agent in S prefers the second matching to the first. This result is a strengthening of a result originally due to Knuth (1976). In a paper by Sasaki and Toda (1992) it is shown that if a marriage problem has more than one stable matchings, then given any one stable matching, it is possible to add agents and thereby obtain exactly one stable matching, whose restriction over the original set of agents, coincides with the given stable matching. We are able to extend this result here to the domain of room-mates problems. We also extend a result due to Roth and Sotomayor (1990) originally established for two-sided matching problems in the following manner: If in a room-mates problem, the number of agents increases, then given any stable matching for the old problem and any stable matching for the new one, there is at least one agent who is acceptable to this new agent who prefers the new matching to the old one and his room-mate under the new matching prefers the old matching to the new one. Sasaki and Toda (1992) shows that the solution correspondence which selects the set of all stable matchings, satisfies Pareto Optimality, Anonymity, Consistency and Converse Consistency on the domain of marriage problems. We show here that if a solution correspondence satisfying Consistency and Converse Consistency agrees with the solution correspondence comprising stable matchings for all room-mates problems involving four or fewer agents, then it must agree with the solution correspondence comprising stable matchings for all room-mates problems.Stable matchings, Room-mate problem

The Core of Directed Network Problems with Quotas

This paper proves the existence of non-empty cores for directed network problems with quotas and for those combinatorial allocation problems which permit only exclusive allocations.combinatorial allocations

Axiomatic Characterization of the Nash and Kalai-Smorodinsky Solution Solutions for Integer Allocation Problems

We consider two-player integer allocation plms and provide axiomatic characterizations of adaptations of the Nash (1950) an Kalai-Smorodinsky (1975) solutions fo such problems. We also relate the theory dveloped for integer allocation problems, to the problem of fair allocation of indivisible objects among two agents. We refer to such problems here, as (two-player) fair matching problems.

Axiomatic characterization of aggregation rules based on consent

In this paper we provide axiomatic chracterzations of the Liberal Rule and the Quota Rule for voting problems where the consent of the candidate is also a factor determining whether the candidate is selected or not.

Existence of Equilibrium for Integer Allocation Problems

In this paper we show that if all agents are equipped with well-behaved discrete concave production functions, then a feasible price allocation pair is a market equilibrium if and only if it solves a linear programming problem. Using this result we are able to obtain a necessary and sufficient condition for existence that requires an equilibrium price vector to satisfy finitely many inequalities. A necessary and sufficient condition for the existence of market equilibrium when the maximum value function is Weakly Monotonic at the initial endowment that follows from our results is that the maximum value function is partially concave at the initial endowment. We also provide a discussion of the results and an alternative solution concept. The alternative solution concept is however, informationally and computationally inefficient.existence, market equilibrium, discrete concave, linear programming