Plurality with elimination, Runoff method, Condorcet criterion.

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Plurality with elimination, Runoff method, Condorcet criterion

Plurality with Elimination 1.Each voter votes for one candidate. 2.A candidate that receiving the majority of the votes is declared the winner. 3.If no candidate receives a majority of the votes, then the candidate/candidates with the fewest votes is dropped from the ballot and a new election is held. 4.You follow this process until a candidate receives a majority of votes.

Example st CACABD 2 nd ACDDAA 3 rd BBBBDC 4 th DDACCB

Run – off Method You only keep the top two first place voters and have an election between those two.

Example st CEBAA 2 nd ADCDC 3 rd BBEBB 4 th ECACD 5 th DADEE

Condorcet Criterion If candidate X can defeat each of the other candidates in a head-to-head vote, then X is the winner of the election. Say you have candidates: A,B,C,D First say A vs. B if B wins Then try B vs. C if B wins Then try B vs. D However, if C won in step 2 then you have to go back and check C vs. A and C vs. D

Example AAABBCC BBBCCBB CCCAAAA

Assignments Classwork – Pg (a,b,c, Run-off), 20 (a,b, Run-off), 31, 33 (a,b, Run – off) Homework - Pg (Run-off), 30 (Run- off), 32, 34 (a,b, Run – off)