Back to Plurality with Runoff Method Labs: Voting and Social Choice. Part 1. Math Alive

Detailed Explanation for Plurality with Runoff Example

  group of 18 group of 12 group of 10 group of 9 group of 4 group of 2
Killians512424
Molson155555
Samuel Adams234133
Guinness441242
Meister Brau323311

Using the methods from the previous section, we find that Molson received the most first-place votes (18), while Killians received the second most (12). We now only consider these two beers. Starting with the first column, 18 voters preferred Molson to Killians, so Molson gets rank 1 and Killians gets rank 2. The next 12 voters preferred Killians to Molson, so Killians gets rank 1 and Molson gets rank 2. If we continue this process with the remaining columns, the following runoff preference schedule is generated:

  181210942
Killians211111
Molson 122222

Adding up all the first-place rankings shows that Killians received 37 first-place votes, while Molson received only 18 first-place votes. Therefore, Killians is the winner under the plurality with runoff voting scheme.


Back to Plurality with Runoff Method Last Modified: August 2008