lattyware:

I will be voting in favour of the Alternative Vote system in the upcoming referendum. I wish to use this to explain why I’ll be doing so.

AV means that you rank the candidates in order of preference. This means that when you vote, you will be voting in a way that represents your views better. We…

I realize you posted this after the election, but perhaps you’d still like to think this one over.

The question really shouldn’t be between IRV and Plurality. Both are pretty bad. To IRV’s credit, it can mitigate the spoiler effect to a degree. But you still get spoilers with IRV once those up-and-comer candidates get more support. You also get a weird effect about 1/5 to 1/6 of the time where you can rank a candidate better to help that candidate or rank a candidate worse to help that candidate (nonmonotonicity). That’s pretty weird.

Instead, consider an even simpler system called Approval Voting. It’s like Plurality/FPTP, but you pick as many candidates as you want. There’s no vote splitting, no spoilers, Centrists are favored, and even losers get a more accurate measure of support. You can find out more about it here: www.electology.org/approval-voting

How does IRV stack up against Approval? You decide: http://www.electology.org/approval-voting-vs-irv

Since you seem like the mathy type, perhaps you might like this comparison of voting systems using Yee’s Voting Visualization Tool: http://www.youtube.com/watch?v=nQxlM-P6ONs