システム情報系 社会工学域
平成25年度 ファカルティ・セミナー
(Faculty Seminar)
日 時 : 2013年7月4日(木) 16:30-18:00
場 所 : 第三学群F棟 3F1115
講演者 : 栗野 盛光 [ ベルリン社会科学研究所
]
司会者 : 石川 竜一郎
演 題 : Do
outside options matter in school choice? A new perspective on the efficiency vs.
strategy-proofness trade-off
<
abstract
>
This paper studies a general school
choice problem in which outside options do not necessarily exist. The
Gale-Shapley student-proposing deferred acceptance mechanism (DA) has played a
critical role not only in theory but also in important practical applications.
An important debate centers around whether it is possible to improve upon DA via
alternative strategy-proof mechanisms. We show that on a general domain of
preferences where all students are able to credibly rank-list their outside or
pseudo-outside options, then no strategy-proof mechanism improving upon DA
exists. It is however possible to construct natural subdomains allowing for
positive results, where student preferences are in part induced by an exogenous
hierarchy of quality tiers. We then identify maximal domains on which it is
possible to improve upon DA without sacrificing strategy-proofness. These
results may help better assess the underpinnings of the three-way tension among
efficiency, stability, and strategy-proofness.