Raph Frank wrote:
On 10/9/08, Dave Ketchum <[EMAIL PROTECTED]> wrote:If there is a near tie among three or more, they often disagree but usually get one of the leaders - matters little since the leaders were about equally deserving.It matters because IRV reinforces the 2 party system. it would be interesting to know what would be the effect of electing a parliament by condorcet voting from single seat districts. It is possible that it would also result in a 2 party system.
Since Condorcet is a majoritarian method (as it needs to be in order to be a good single-winner method), the resulting parliament would also be majoritarian. This means that a party whose candidates consistently got low support in all districts would find none of those elected.
But Condorcet is also a better single-winner method than Plurality, so the candidates would be better representatives of the majority. They would probably be good compromise candidates, so the parliament would be less party-based than one elected by PR methods.
This might not be all that good for traditional parliaments; I don't know if the majoritarian nature would lessen competition (except in dominant-party states, where using Condorcet would be an improvement on Plurality in that respect), but it would reduce the voice of the minority.
It might be a good choice for an upper house decided to be a moderating counterweight to a populist lower house.
However, based on certain assumptions, IRV is 2 party reinforcing. Also, Australia gives "experimental" evidence that IRV leads to a 2 party system. Condorcet wouldn't necessarily, so that is a good reason to at least try it.
It's possible that IRV is a bad single-winner method precisely because STV is a good PR method (with many seats). In STV, one doesn't need to find a candidate that covers a large area of opinion space, since other candidates can be used to cover those areas, but in IRV there are no other positions to be used in such a manner. I'm not sure if this is the reason, but it would fit well with my simulation results that "majoritarian IRV" (eliminate until only k remains for council size k) is a surprisingly good PR method, at least in absence of strategy.
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