PP-2007-23: Vote Manipulation in the Presence of Multiple Sincere Ballots

PP-2007-23: Endriss, Ulle (2007) Vote Manipulation in the Presence of Multiple Sincere Ballots. [Report]

[thumbnail of Full Text]
Text (Full Text)

Download (181kB) | Preview
[thumbnail of Abstract] Text (Abstract)

Download (1kB)


A classical result in voting theory, the Gibbard-Satterthwaite
Theorem, states that for any non-dictatorial voting rule for choosing
between three or more candidates, there will be situations that give
voters an incentive to manipulate by not reporting their true
preferences. However, this theorem does not immediately apply to all
voting rules that are used in practice. For instance, it makes the
implicit assumption that there is a unique way of casting a sincere
vote, for any given preference ordering over candidates. Approval
voting is an important voting rule that does not satisfy this
condition. In approval voting, a ballot consists of the names of any
subset of the set of candidates standing; these are the candidates the
voter approves of. The candidate receiving the most approvals wins. A
ballot is considered sincere if the voter prefers any of the approved
candidates over any of the disapproved candidates. In this paper, we
explore to what extent the presence of multiple sincere ballots allows
us to circumvent the Gibbard-Satterthwaite Theorem. Our results show
that there are several interesting settings in which no voter will
have an incentive not to vote by means of some sincere ballot.

Item Type: Report
Report Nr: PP-2007-23
Series Name: Prepublication (PP) Series
Year: 2007
Uncontrolled Keywords: voting theory; approval voting; strategy-proofness
Depositing User: Ulle Endriss
Date Deposited: 12 Oct 2016 14:36
Last Modified: 12 Oct 2016 14:36
URI: https://eprints.illc.uva.nl/id/eprint/257

Actions (login required)

View Item View Item