2
Abstract
Voters are sovereign to the degree that they can express their approval for any set
of candidates and, by so doing, help elect or prevent the election of candidates. While
voter sovereignty is maximized under approval voting (AV), AV can lead to
• a plethora of outcomes, depending on where voters draw the line between
acceptable and unacceptable candidates; and
• Condorcet losers and other lesser candidates, even in equilibrium.
But we argue that voters’ judgments about candidate acceptability should take
precedence over standard social-choice criteria, such as electing a Condorcet or Borda
winner. Among other things, we show that
• sincere outcomes under all voting systems considered are AV outcomes, but not
vice versa;
• a Condorcet winner’s election under AV is always a strong Nash-equilibrium
outcome but not under other systems, including those that guarantee the election
of Condorcet winners if voters are sincere.
Keywords: approval voting; elections; Condorcet winner/loser; Nash equilibrium.
Convention