1.5 Weighted Voting and Voting Power Ms. Magné́ Discrete Math
Review of Group Ranking Plurality Majority Borda Runoff Sequential Runoff Condorcet Pairwise Approval
Weighted Voting Weighted Voting – this occurs when some members of the voting population have more votes then others.
Weighted Voting Ex. The student council is composed of one representative from each class. Each member gets votes proportionate to their class size. The sophomore representative gets 5 votes, the junior gets 3, and the senior gets 3. Six votes are needed to pass an issue. 1) List all the coalitions (all possible collections of votes) 2) List all winning coalitions
Essential Members Essential Members – members who are necessary for an issue to pass. (If a member is taken out of a coalition and there are no longer enough votes to pass, then the member is said to be essential) 3) Who are the essential members in the coalition {So, Sr; 8}? 4) Who are the essential members in the coalition {So, Jr, Sr; 11}?
Power Index Power Index – a measure of a members power. A member’s power index is equal to the number of coalitions a member is essential to. 5) List the power index for each member of the student council. So. = Jr. = Sr. =