Talk:Schulze STV: Difference between revisions

 

::::: Keep in mind that in the party list case, you can simplify the calculations so much that it can be done by hand (or even mentally, if the example is really simple). You can think of each pairwise comparison as "should this party get one more seat or that party?" (this directly follows from the fact that each comparison is between winner sets that differ by exactly one candidate). Further, the winner of a comparison is simply determined by checking which of the two benefitting parties has more votes per the max seats they're trying to take in that comparison, because none of the other parties has any preference between those two, and because each of the two parties will prefer to vote manage in favor of the winner set when their party would get more seats. Because this is really equivalent to finding a highest average, we want to think about three cases: when a winner set gives a party their D'Hondt share, and when it goes over or under. If it goes over for one party and under for the other, then the under-party can get a better average i.e. If for two parties A and B, A's proper share is 10 and B's 8, and we compare winner sets with A at 15 and B at 7, we know that based on D'Hondt, A simply couldn't have had that many votes per seat. Maybe let me try to show you why the D'Hondt formula is equivalent to vote management: when a party gets its first seat, its votes are divided by 2. This never made sense to me until I thought of it as the party essentially seeing whether or not it could split more of its votes between 2 seats such that it had more votes per seat than any other party. When it gets that second seat, its votes get divided by 3, because it's looking to play for 3 seats now. In a system like regular STV, when parties have to decide whether to vote manage, they make exactly this type of calculation i.e. can we put more votes in each seat than anyone else. It's just that in D'Hondt, you first get the seats that you can get and then if your attempt to take an additional one fails, no harm, whereas in STV, if you spread too thin you get nothing. (Just to clarify, by vote management in STV I'm referring to the Hylland type where a party might tell half of its voters to bullet vote one of its candidates and the other half to bullet vote the other guy.) I can maybe create some graphics later and link them to you if I can think of how to demonstrate it. [[User:BetterVotingAdvocacy|BetterVotingAdvocacy]] ([[User talk:BetterVotingAdvocacy|talk]]) 14:24, 25 March 2020 (UTC)