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Complexity of control by partitioning veto elections and of control by adding candidates to plurality elections

  • Cynthia Maushagen
  • Jörg Rothe
Article
  • 54 Downloads

Abstract

Control by partition refers to situations where an election chair seeks to influence the outcome of an election by partitioning either the candidates or the voters into two groups, thus creating two first-round subelections that determine who will take part in a final round. The model of partition-of-voters control attacks is remotely related to “gerrymandering” (maliciously resizing election districts). While the complexity of control by partition has been studied thoroughly for many voting systems, there are no such results known for the important veto voting system. We settle the complexity of control by partition for veto in a broad variety of models. In addition, by giving a counterexample we observe that a reduction from the literature (Chen et al. 2015) showing the parameterized complexity of control by adding candidates to plurality elections, parameterized by the number of voters, is technically flawed, and we show how this reduction can be adapted to make it correct.

Keywords

Computational social choice Voting Veto election Control complexity 

Mathematics Subject Classification (2010)

91B14 68Q17 68Q15 68T99 

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Notes

Acknowledgements

We thank the AMAI, AAMAS-2017, ECAI-2016, and ISAIM-2016 reviewers for many helpful suggestions. This work has been supported in part by DFG grant RO-1202/15-1.

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Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.Institut für InformatikHeinrich-Heine-Universität DüsseldorfDüsseldorfGermany

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