Condorcet Election Decision Procedure

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Condorcet Election Decision Procedure

• Avoiding the agenda effect?

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Condorcet Winner Criterion(CWC)

• Each pair of candidates should be considered
  in its own separate election and the winner
  determined. If there is one candidate who wins
  over each of the others in these 2-way contests,
  that candidate (called a Condorcet candidate)
  should be the winner of the election.

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The Infamous Pizza Election!
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Condorcet and Pizza

• How many two way contests are needed?
• (If you arent sure, try it for 3
  alternatives.)
• List each contest, with the winner and vote
  totals.

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Condorcet results
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Digraph (Directed Graph) Model for Condorcet
Results

• P S
• H V

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Vacation Decision
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Eliminating the Agenda Effect?

• Whenever the agenda effect is present, there will
  not be a Condorcet candidate, and hence
  Condorcets method will not choose a winner!
• (If there were a Condorcet candidate, he would
  win from the point where he entered any agenda.)
• Condorcet does not eliminate the agenda effect!

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Decisiveness

• An election decision procedure is said to be
  decisive if it always produces a winner from
  among the alternatives.
• Condorcet is not decisive. If there is no
  Condorcet candidate, there will be no winner. (If
  the agenda effect is present, for example.)