On Thu, Aug 21, 2008 at 7:23 PM, Kristofer Munsterhjelm <[EMAIL PROTECTED]> wrote: > The decoy list strategy appears because it's possible to vote for a > different national party and regional party (constituency candidate), which > leads to an overhang that can be exploited to turn top-up into parallel MMP. > > A simple countermeasure is to weight the vote pairs in a way that if you got > what you wanted in the constituency part, your say is diminished in the list > part.
This isn't possible though. Fundamentally, FPTP means that a candidate can get 1 full seat while only being supported by 1/2 a seat's worth of voters (and often less). Independents make it even worse (and as you say decoy lists exploit this). > For a single seat election, STV would reduce to IRV. For 1000 ballots, the > Droop quota would be (1000/(1+1)) + 1 = 1000 * 0.5 + 1 = 501, which seems > right, considering a majority is 50% + 1. It depends on how you want to look at it. If there are 100 seats, then the quota is 1/101 of the votes cast. This works out as 100/101 of the votes cast in each constituency (assuming equal turnout). Thus unless a local candidate hit ~99% of the local vote, he wouldn't actually reach the (national) STV quota. In the STV case, candidates could reasonably be expected to hit the national quota and so fully be entitled to a seat as they represent one full seats worth of voters. > If the voters vote a straight party ticket, wouldn't the method reduce to > party list PR? Well, a strange sort of party list PR that allocates some of > the seats according to a quota rule and others according to a divisor > method, but party list PR nonetheless. Right. One of the features of STV is that parties tend to try not to alienate (much) the supporters of other parties. In 2007, the Greens got 4.7% of the FPV and 3.6% of the seats. SF got more FPV (6.9%) but fewer seats 2.4%. This was because none of the other parties' supporters were willing to transfer to them, due to their links to the IRA. It is probably a matter of opinion if that is a good or bad feature. ---- Election-Methods mailing list - see http://electorama.com/em for list info
