1. Warm-up
Find the Banzaf power index for the following Information: A 35% B 30% C 25% D 10%

2. Shapley – Shubik Power Index
DM.13

3. Pivotal voter: add voters to a coalition one at a time, the PIVOTAL VOTER is the first person added to the coalition that makes it a winning coalition.

4. Identify the Pivotal Voter
[5:3, 2, 2, 1]
Find the pivotal voter in each coalition:
A, B, C, D
A, D, C, B
D, A, B, C
D, C, A, B

5. Shapley-Shubik Index
# of times the voter is pivotal in some permutation of the voters _____________________________________ Total # of permutations of the voters

6. Example
[4: 3, 2, 1]

7. Assignment
Classwork: pg , 27, 29 Homework: Pg , 28, 30