Using STAR in a PR method seems guaranteed to require parties to run at least one more candidate than the number of seats they’re expected to win. In a 5-seat district, where Party A is the minority party and expects to win 2 seats, it should have 3 candidates, so that for the final seat, Party B, the majority party, doesn’t steal that seat in the runoff.
One way to counter this might be to weight the runoff towards the ballots that are less satisfied i.e. a ballot that is only 1/5 points satisfied should have more of a vote in the runoff than a ballot that is 4/5 points satisfied. Taken to the extreme, this would just end up being Score Voting, so maybe a compromise can be found. But is it even desirable to have a runoff in PR?
This is one earlier attempt:
but it seems too complex to be viable. Maybe I’m just not understanding it though.
Also, would including a runoff make the PR method more viable? An appeal to majority rule is powerful, but complexity is a factor.
In fact, one way to do a STAR-slightly PR method would be to just run STAR multiple times, but each time, the votes in the runoff are reweighted using the Hare Quota. So for example, in a 5-seat district, the majority wins the runoff for the first seat, and then all majority ballots lose 20% of their runoff vote power. Repeat for each seat. It’s not PR, but it allows for some minority influence over the seats won by the majority.