Presentation on theme: "1.4 Arrow’s Conditions and Approval Voting"— Presentation transcript:
11.4 Arrow’s Conditions and Approval Voting Ms. MagneDiscrete Math
2Arrow’s ConditionsWe have talked about many different ways to rank voting preferences, but not all of them have been fair.Kenneth Arrow came up with 5 conditions that are necessary for a fair group ranking
3Arrow’s Conditions1) Nondictatorship – one person’s votes should not be better then another person’s votes2) Individual Sovereignty – everyone shouldbe allowed to order their choices in anyorder they want3) Unanimity – if everyone prefers one choiceto another, then the group ranking shoulddo the same
4Arrow’s Conditions4) Freedom from Irrelevant Alternatives – if a choice is removed, the order in which the others are ranked should not change5) Uniqueness of Group Ranking – Themethod of producing group ranking shouldgive same result whenever it is applied to agiven set of preferences. (not rolling a dice)
5Approval VotingApproval Voting – voters are allowed to vote for as many or as few choices as they like, but they do not rank them. Winner is whoever has the most votes.
6Approval VotingEx. Find the winner if everyone approves of their first and third choices.A B C DB C B BC D D CD A A ACThe Approval Winner is _____.
7Approval Voting Ex. Use the Approval Method to find the winner. Voter 1Voter 2Voter 3Voter 4Voter 5AXBC