Hi I am afraid a proportional approach in the first round wouldnt work, it opens up for strategic voting. Say we have an election with A, B, C. 45 A 30 B A 25 C B A
The first round in a 2-seat election the quota is 34 votes If we would have a two-round proportional election, then B would win in the second round. So A's voters find this out and decide to change their preferences and 10 of the voters of A vote for C So we have 35 A 30 BA 25 CBA 10 CA C and A meet in the second round, where A wins. PZ 2013/2/4 Kristofer Munsterhjelm <km_el...@lavabit.com>: > On 02/04/2013 02:40 PM, Peter Zbornik wrote: >> >> Being a green party member (although a Czech one and not US), I would >> advocate only the top-two-run-off >> variant of IRV, i.e. elimination of the candidates and transfer of >> votes until two remain, no quota for election (or quota=100%) except >> for the case where one candidate has more than 50% of first >> preferences. >> >> The top two candidates would meet in a second round in IRV. >> A candidate would be elected if he/she would get more than 50% of the >> votes. >> >> Empty votes would count as valid votes in both first and second round. >> >> If no candidate would be elected in second round new elections would take >> place. >> >> The advantages of the proposed election system are >> 1) the voters are given a chance to concentrate only on two candidates >> in the second round, and are thus allowed to change their preferences. >> 2) blank votes together with IRV might make the candidates less >> polarized, as, given a large number of blank votes, the candidate with >> the highest number of votes in the second round would have to rely on >> the second preferences of the voters for the opposing candidate in >> order to get 50%+ votes. > > > Perhaps this method would work for runoffs if you can get a more > sophisticated base method through, say for internal elections: > > - Run a single-winner election using your method of choice. Call the winner > w_1. > - Use a proportional ranking method to determine the second runoff candidate > w_2 so that the virtual council {w_1, w_2} represents as much as possible of > the population. > - Have a runoff between w_1 and w_2. > > If w_1 is a strong winner, he'll win in the runoff. If he's a weak winner > (e.g. the "bland politician being everybody's second choice" scenario), w_2 > wins. > > In IRV, this would be like running two-member STV where the IRV winner is > barred from being disqualified. > > There could be a problem, though, in a society that has a bland centrist > politician and strong left- and right-wing candidates. Since the runoff can > only hold two candidates, either the left-wing or the right-wing candidate > would be disqualified; and if the bland politician is sufficiently bland, > then the wing candidate would pretty much win by default. IRV "solves" this > by not letting center-squeezed candidates win in the first place. Another > option is to have multiple candidates in the runoff, but then the simplicity > and strategy resistance properties of the second round go away. > ---- Election-Methods mailing list - see http://electorama.com/em for list info