Social Choice and Welfare

, Volume 47, Issue 3, pp 559–587 | Cite as

Strategic voting in multi-winner elections with approval balloting: a theory for large electorates

  • Jean-François LaslierEmail author
  • Karine Van der Straeten
Original Paper


We propose a theory of strategic voting in multi-winner elections with approval balloting. With a tiny probability that any vote might be misrecorded, best responses involve voting by pairwise comparisons. Two candidates play a critical role: the weakest expected winner and the strongest expected loser. Expected winners are approved if and only if they are preferred to the strongest expected loser and expected losers are approved if and only if they are preferred to the weakest expected winner. At equilibrium, if any, a candidate is elected if and only if he is approved by at least half of the voters. With single-peaked preferences, an equilibrium always exists, in which the first candidates according to the majority tournament relation are elected. The theory is applied to individual data from the 2011 Regional Government election in Zurich.


Vote Rule Condorcet Winner Approval Vote Plurality Rule Parliamentary Election 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Jean-François Laslier
    • 1
    Email author
  • Karine Van der Straeten
    • 2
  1. 1.Paris School of Economics and CNRSParisFrance
  2. 2.Toulouse School of EconomicsCNRS and Institute for Advanced Study in ToulouseToulouseFrance

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