Mat 102

Worksheet

Please work in groups!

1. This is the preference schedule taken from problem 42:

Number of Votes	6	5	4	2
1^st place	A	B	C	D
2^nd place	C	D	A	C
3^rd place	B	C	D	B
4^th place	D	A	B	A

Rank the candidates using

a) The extended plurality method

b) The extended Borda count method

c) The extended plurality with elimination

d) The extended Pairwise comparisons

Review questions:

1. Is there a majority candidate?________ Which methods fail the Majority criterion?

2. Is there a Condorcet candidate? _______ Which methods fail the Condorcet Criterion?

3. Show that the plurality method fails the IIA criterion.

4. Show that Instant run-off fails the IIA criterion. (Hint: eliminate B.)

5. Why does the Pairwise comparisons method comply with the IIA criterion?