Abstract
We consider Pareto optimal matchings (POMs) in a many-to-many market of
applicants and courses where applicants have preferences, which may
include ties, over individual courses and lexicographic preferences over
sets of courses. Since this is the most general setting examined so far
in the literature, our work unifies and generalizes several known
results. Specifically, we characterize POMs and introduce the Generalized Serial Dictatorship Mechanism with Ties (GSDT)
that effectively handles ties via properties of network flows. We show
that GSDT can generate all POMs using different priority orderings over
the applicants, but it satisfies truthfulness only for certain such
orderings. This shortcoming is not specific to our mechanism; we show
that any mechanism generating all POMs in our setting is prone to
strategic manipulation. This is in contrast to the one-to-one case (with
or without ties), for which truthful mechanisms generating all POMs do
exist.
Original language | English |
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Pages (from-to) | 700-721 |
Number of pages | 22 |
Journal | Theory of Computing Systems |
Volume | 59 |
Issue number | 4 |
Early online date | 30 Apr 2016 |
DOIs | |
Publication status | Published - 1 Nov 2016 |
Keywords
- Many-to-many matching
- Pareto optimality
- Serial dictatorship
- Truthfulness