Building the party list by successive STV elections, with increasing N, definitely seems the way to make a list that will give the most proportional results regardless of how many seats the party wins. House nonmonotonicity, though it can occur, probably won't happen often, and, if that's the case, then what will happen is that when the N-candidate STV count is done, there will be 1 new candidate among those N, and he will be the Nth candidate on the list. I was previously suggesting to always give the already chosen candidates precedence--the N-1 candidates would keep their list positions even if they weren't all among the N current STV winners. But here's a better precedence rule: If N is less than the current number of seats the party has, then the N candidate STV count takes precedence, and its N winners are the list members so far. Any new ones would be ordered, after the positions of the existing list candidates, by the use of a single-winner method. Either most 1st place votes, or a good single-winner method repeated for each next rank position. If N is equal to or greater than the current number of seats that the party has, then the candidates already in the list take precedence, when house nonmonotonicity occurs. They keep their positions, and a single-winner method is used to determine which new candidate among the N shall be the Nth candidate in the list. *** Those precedence rules recognize that your current number of parliamentary seats is the most likely number for the coming election. *** Mike Ossipoff
