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 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.

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.

Consistency and the Competitive Outcome Function

In this paper we are interested in the social choice theory of allocating resources, which are available and can be consumed in integer units only. Since goods are available in integer units only, the social choice theory for such problems cannot exploit any smoothness property, which may otherwise have been embedded in the preferences of the agents. This makes the outcome function approach for the study of such problems quite compelling. Our purpose here is to study outcome functions, which are efficient and consistent. We provide an example to show that the competitive social choice function may not be converse consistent. The competitive outcome function is easily observed to be efficient, consistent and converse consistent. What we are able to show here is that any efficient and consistent outcome function which is “reasonably well-behaved” for two-agent problems, must be a sub-correspondence of the competitive outcome function. Our proof of this result requires the converse consistency of the competitive outcome function.social choice, outcome function, efficient, consistent, converse consistent

Manipulation of market equilibrium via endowments

In this paper we show that in an exchange economy with quasi-linear preferences it is possible to manipulate market equilibrium by destroying and withholding ones initial endowments.