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 M3//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20231009T073355Z
DTSTART:20231011T160000Z
DTEND:20231011T170000Z
SUMMARY:MET Seminar - Josue Ortega (Queen’s\, Belfast)
UID:{http://www.columbasystems.com/customers/uom/gpp/eventid/}z1te-llw4l0
 5h-l6uxi4
DESCRIPTION:Title: The Limits of School Choice with consent (joint with G
 abriel Ziegler)\n\nAbstract: The deferred acceptance (DA) algorithm is u
 sed all around the world to assign pupils to schools due to its stabilit
 y and strategy-proofness. However\, DA can generate an assignment that i
 s Pareto inefficient for students and\, in some cases\, it may assign al
 l students to their worst or second worst school. The inefficiency of DA
  has been also documented in real life. Kesten (2010\, QJE) proposed an 
 influential modification of DA\, known as efficiency-adjusted deferred a
 cceptance (EADA)\, which fixes the Pareto inefficiency of DA. A vast lit
 erature has now shown that EADA is not only Pareto efficient\, but also 
 satisfies a plethora of desirable properties both theoretically and in t
 he lab. For these reasons\, EADA is to be implemented in Flanders. Despi
 te these good properties\, we show that EADA can generate allocations th
 at are significantly rank-inefficient and unequal. In particular\, we pr
 ove that for any number of students\, there exists a school choice probl
 em where half of the students are allocated to a school in the bottom ha
 lf of their preferences according to EADA\, even though a different allo
 cation assigns all but one student to their top school\, and no student 
 to a school worse than their second choice. Furthermore\, we analyze ran
 dom\, iid one-to-one matching problems. In our main Theorem\, we approxi
 mate the asymptotic expected average rank in EADA\, which is in the orde
 r of $\\log(n!)/n$. This result has an interesting corollary: the qualit
 y of student placement in {EADA is asymptotically the same as in DA}\, w
 hich implies that the size of the efficiency gains of EADA over DA vanis
 h when the number of students is large. This result explains the small e
 fficiency gains of EADA versus DA documented empirically (Ortega and Kle
 in\, 2023 GEB).\n\nManchester Economic Theory (MET) schedule: http://dav
 iddelacretaz.net/seminars/\n\nSpeaker website: https://www.josueortega.c
 om/
STATUS:TENTATIVE
TRANSP:TRANSPARENT
CLASS:PUBLIC
LOCATION:Boardroom 2.016\, Arthur Lewis Building\, Manchester
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