It’s hard to disagree with proportional voting methods, but I think you’re going down the wrong path with IRV. It does not avoid the spoiler effect. In fact, the Burlington election happened the way it did because the Republican was the spoiler. Had conservatives not ranked the Republican as their honest favorite, then the Democrat would have won. That’s a much better outcome for them than the Progressive, which they got directly because they voted their favorite. Had conservatives voted dishonestly and ranked the Democrat first, they would have gotten a better outcome.
Now IRV is a complicated algorithm. Sure, everybody can rank, but most people can’t explain its process. Also, it can be difficult to explain how the spoiler effect works with IRV because it’s so complicated. Luckily, here’s a video:
If you’re really looking for a single-winner method, I’d go with approval voting. You pick as many candidates as you want. Most votes wins. You can always support your honest favorite no matter what. Admittedly, it’s not perfect. No method is. But being able to see an accurate reflection of support of all the candidates is very important. Plus, it prefers moderates (whatever moderate means within a particular electorate). You can see how approval voting compares to IRV here.
A cool video on approval voting:
To be fair, IRV is better than plurality because it at least mitigates the spoiler effect compared to plurality voting. When the alternative candidate has little support, it can be alright. Then again, plurality voting sets a pretty low bar.
STV works pretty decently for a proportional system. Although I think there’s better, it’s surely better in the multi-winner world than IRV is in the single-winner world. I’d agree that STV does a nice job of dealing with gerrymandering, but that’s only to the extent that you have more seats elected at once — crucial for any proportional voting method. You should aim for at least five seats according to work by David Farrell and Douglas Amy, whom I happen to agree with on this one.
Great job bashing plurality voting. It sucks!