Yazar "Ozkal-Sanver, Ipek" seçeneğine göre listele
Listeleniyor 1 - 11 / 11
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Characterization of the core in full domain marriage problems(Elsevier Science Bv, 2014) Nizamogullari, Duygu; Ozkal-Sanver, IpekIn this paper, we study the core of two-sided, one-to-one matching problems. First, in a model in which agents have strict preferences over their potential mates and are allowed to remain single, we characterize the core as the unique solution that satisfies individual rationality, Pareto optimality, gender fairness, consistency, and converse consistency. Next, in a model that relaxes the constraint that agents have strict preferences over their potential mates, we show that no solution exists that satisfies Pareto optimality, anonymity, and converse consistency. In this full domain, we characterize the core by individual rationality, weak Pareto optimality, monotonicity, gender fairness, consistency, and converse consistency. (C) 2014 Elsevier B.V. All rights reserved.Öğe Coalitional stability and efficiency of partitions in matching problems(Springer, 2011) Nizamogullari, Duygu; Ozkal-Sanver, IpekA-zkal-Sanver (Theory Decis 59:193-205, 2005) studies stability and efficiency of partitions of agents in two-sided matching markets in which agents can form partitions by individual moves only, and a matching rule determines the matching in each coalition in a partition. In this study, we present the relationship between stability and efficiency of partitions that is analyzed for several matching rules and under various membership property rights codes, now allowing coalitional moves.Öğe Consistent enlargements of the core in roommate problems(Springer, 2015) Nizamogullari, Duygu; Ozkal-Sanver, IpekIn this paper, we study consistent enlargement of a solution. By computing it, one actually evaluates the extent to which the solution would have to be expanded in order to be well-defined and consistent. We show that the union of stable matchings and the matching recommended by a single-valued, well-defined, individually rational, and consistent solution is a minimal consistent enlargement of the core. Although individual rationality is sufficient it is not a necessity. Next, we show that for any fixed order on the set of agents in the society, the union of stable matchings and the serial dictatorship matching is a minimal consistent enlargement of the core.Öğe Ensuring pareto optimality by referendum voting(Springer, 2006) Ozkal-Sanver, Ipek; Sanver, M. RemziWe consider a society confronting the decision of accepting or rejecting a list of (at least two) proposals. Assuming separability of preferences, we show the impossibility of guaranteeing Pareto optimal outcomes through anonymous referendum voting, except in the case of an odd number of voters confronting precisely two proposals. In this special case, majority voting is the only anonymous social choice rule which guarantees Pareto optimal referendum outcomes.Öğe Impossibilities for roommate problems(Elsevier, 2010) Ozkal-Sanver, IpekWe establish three impossibility results for roommate problems. First, no single valued solution is Pareto optimal and anonymous. Next, no solution satisfies Pareto optimality, anonymity and converse consistency. Finally, no pseudo-refinement of the core satisfies consistency (C) 2010 Elsevier B.V. All rights reservedÖğe Manilulation via endowments in university-admission problem(Economics Bulletin, 2011) Iris, Doruk; Ozkal-Sanver, IpekWe consider a two-sided many-to-one matching model where universities offer scholarships to students. We show that every stable matching rule is manipulable by a university via destroying endowments under a fairly wide class of scholarship rules. Furthermore, we show that the set of Nash equilibria of the destruction game and the set of stable matchings may be disjoint.Öğe The manipulability of matching rules via segmentation(Springer, 2007) Sertel, Murat R.; Ozkal-Sanver, IpekOur matching problems feature agents with endowments facing certain division rules. At any matching, the endowments of agents are reallocated between the matched pairs according to some given division rule, and this opens doors to an iterated matching problem and rematching, and to manipulation of some matching rules via segmentation. In this form of manipulation a coalition breaks off from the rest, matches within itself and rejoins the complementary coalition for a rematching at the new endowment profile. Under certain division rules this may benefit the coalition who breaks off without hurting the complementary coalition. Furthermore, both may benefit by first matching internally and then rejoining for a new match.Öğe Minimal conversely consistent extension of the men-optimal solution(Springer, 2013) Ozkal-Sanver, IpekThis study pertains to two-sided, one-to-one matching problems and considers the best-known solution concept: the men-optimal solution. The men-optimal solution fails to satisfy consistency as well as converse consistency. Furthermore, the minimal consistent extension of the men-optimal solution equals the core. In this article, we compute the minimal conversely consistent extension of the men-optimal solution as a correspondence which associates with each problem the set consisting of the men-optimal matching, and all stable and men-barterproof matchings for this problem.Öğe Nash implementation via hyperfunctions(Springer, 2006) Ozkal-Sanver, Ipek; Sanver, M. RemziHyperfunctions are social choice rules which assign sets of alternatives to preference profiles over sets. Therefore, they are more general objects compared to standard (social choice) correspondences. In fact, every correspondence can be expressed in terms of an equivalent hyperfunction. We give a partial characterization of Nash-implementable hyperfunctions and explore the conditions under which correspondences have Nash-implementable equivalent hyperfunctions. While the strength of these conditions depends on the axioms used to extend preferences over alternatives to sets, they are at most as strong as the conjunction of Maskin monotonicity with the no veto power condition. Thus, our approach expands the set of Nash-implementable social choice rules. In fact, social choice rules such as the majority rule and the top cycle are Nash-implementable through their equivalent hyperfunctions, while they are not Maskin-monotonic, and thus, not Nash-implementable in the standard framework.Öğe A new monotonicity condition for tournament solutions(Springer, 2010) Ozkal-Sanver, Ipek; Sanver, M. RemziWe identify a new monotonicity condition (called cover monotonicity) for tournament solutions which allows a discrimination among main tournament solutions: The top-cycle, the iterated uncovered set, the minimal covering set, and the bipartisan set are cover monotonic while the uncovered set, Banks set, the Copeland rule, and the Slater rule fail to be so. As cover monotonic tournament solutions induce social choice rules which are Nash implementable in certain non-standard frameworks (such as those set by Bochet and Maniquet (CORE Discussion Paper No. 2006/84, 2006) or A-zkal-Sanver and Sanver (Social Choice and Welfare, 26(3), 607-623, 2006), the discrimination generated by cover monotonicity becomes particularly notable when implementability is a concern.Öğe A note on roommate problems with a limited number of rooms(Springer Heidelberg, 2022) Nizamogullari, Duygu; Ozkal-Sanver, IpekClassical roommate problems define individual rationality by conceiving remaining single as the outside option. This conception implicitly assumes that there are always some empty rooms to be shared. However, there are many instances when this is not the case. We introduce roommate problems with a limited number of rooms, where the outside option is having no room. In this general framework, we show that the core equals the set of Pareto optimal and stable matchings.
