What is your preference My preference list is B>D>C>A>E How to determine who is the most popular hero?
What is your preference ? My preference list is B > D > C > A > E How to determine who is the most popular hero?
Example 1:Suppose we have 55 students and assume their preferences are recorded in the following table. Choice students 18 12 10 9 4 2 1st Choice A B C D E E 2nd Choice D E B C B 3rd Choice E D E E D 4th Choice C C D B B 5th Choice B A A A A A
A D E B C 10 A B E C D 9 A C D E B 12 2nd Choice D B C 3rd Choice E D D 4th Choice C C B 5th Choice B A A 1 A E E st Choice 18 4 2 students Choice Example 1: Suppose we have 55 students and assume their preferences are recorded in the following table
How to determine who is the most popular hero? Vote Outcome or Individual Preferences Social Choice B C C Voting System A D A C or C B A Social Choice B E E E Procedure D A D B E We shall illustrate the five common social choice procedures with this single example
A D B E E E C B A … D A D B C C … Individual Preferences Voting System or Social Choice Procedure Vote Outcome or Social Choice A C B D E We shall illustrate the five common social choice procedures with this single example. How to determine who is the most popular hero?
Social Choice Procedure 1: Plurality Voting Plurality voting is the social choice procedure that most directly generalizes the idea of simple majority vote from the easy case of two candidates to the complicated case of three or more candidates. The idea is simply to declare as the social choice(s) the candidate with the largest number of first-place rankings in the individual preference lists
Social Choice Procedure 1: Plurality Voting Plurality voting is the social choice procedure that most directly generalizes the idea of simple majority vote from the easy case of two candidates to the complicated case of three or more candidates. The idea is simply to declare as the social choice(s) the candidate with the largest number of first-place rankings in the individual preference lists
Social Choice Procedure 1: Plurality Voting students Choice 18 12 10 9 4 2 1st Choice A B C D E E 2nd Choice D E B C B 3rd Choice E D E E 4th Choice C C D B B 5th Choice B A A A A A Since candidate A occurs at the top of the most lists(18),it is the social choice when the plurality method is used
Social Choice Procedure 1: Plurality Voting Since candidate A occurs at the top of the most lists(18), it is the social choice when the plurality method is used. A D E B C 10 A B E C D 9 A C D E B 12 2nd Choice D B C 3rd Choice E D D 4th Choice C C B 5th Choice B A A 1 A E E st Choice Choice 18 4 2 students