2022 - Reprints: Operations Strategy and Sustainability Management
Stable matching of student-groups to dormitories, European Journal of Operational Research, 302(1), 50-61, 2022
N. Perach and S. Anily
(Reprint No. 393)
Research No.: 01222100
This paper generalizes results of former papers on the assignment of students to dormitories, under an entrance criterion, by allowing students to apply in groups. A group-application means that its applicants ask to be assigned at the same dormitory, and otherwise they prefer living off-campus. The underlying assumption in our model is that the dormitories share a common preference over the student-groups, which is given by a strictly increasing ranking of their credit scores. The definition of a quasi-stable outcome is adjusted in order to incorporate student-group applications, and we prove that such an outcome always exists. Furthermore, a polynomial-time algorithm that finds all the quasi-stable outcomes, is proposed. Apparently, not all properties of the single students' model continue to hold under group-applications. Finally, we consider the incentive compatibility property of the proposed algorithm, and describe a specific quasi-stable outcome for which no subset of student-groups can gain by misrepresenting their preferences over the dormitories.
Social and monopoly optimization in observable queues, Operations Research, 68(4), 1178-1198, 2020
R. Hassin & R. I. Snitkovsky
(Reprint No. 400)
Naor’s celebrated paper studies customer decisions in an observable M/M/1 queue in which joining-customers utility is linearly decreasing with the joining position. Naor derives the optimal threshold strategies for the individuals, social planner, and monopolist and proves that the monopoly optimal threshold is (weakly) smaller than the socially optimal threshold, which is (weakly) smaller than the individually optimal one. Studies show, based on numerical observations and/or ad hoc proof techniques, that this triangular relation holds within various specific setups, in which the queuing process is not M/M/1 and/or when the utility is not linear. We point out properties that imply the aforementioned result in Naor’s model and its extensions and suggest model applications for our findings. Our formulation gives strictly stronger results than those currently appearing in the literature. We further provide simple examples in which the inequality does not hold.
