I don’t see why you say Sequential Proportional Approval Voting gives little incentive for strategic voting. If I am confident a candidate I support is going to be elected in the first round, it’s in my interest not to vote for them so that my votes for other candidates I support will count for more. Of course, if a lot of people think like this then a popular candidate could actually lose, so there is a bit of a brinksmanship dynamic going on here. I don’t think that is a good thing.
You have to be careful with this argument because it’s valid for any candidate-based proportional voting method. All such voting methods rely on the influence of voters who strongly support candidates who get elected being reduced with regard to other candidates, so all of them have such an incentive. (It takes different forms in different voting methods; in STV the incentive isn’t to forgo ranking such a candidate altogether, it’s to rank such a candidate second or third.) This does not mean the incentive for free-riding is equally strong under all candidate-based proportional voting methods, however, and I do think that strategy is more important under SPAV than under some forms of STV.
I don’t see why you say Sequential Proportional Approval Voting gives little incentive for strategic voting. If I am confident a candidate I support is going to be elected in the first round, it’s in my interest not to vote for them so that my votes for other candidates I support will count for more. Of course, if a lot of people think like this then a popular candidate could actually lose, so there is a bit of a brinksmanship dynamic going on here. I don’t think that is a good thing.
You have to be careful with this argument because it’s valid for any candidate-based proportional voting method. All such voting methods rely on the influence of voters who strongly support candidates who get elected being reduced with regard to other candidates, so all of them have such an incentive. (It takes different forms in different voting methods; in STV the incentive isn’t to forgo ranking such a candidate altogether, it’s to rank such a candidate second or third.) This does not mean the incentive for free-riding is equally strong under all candidate-based proportional voting methods, however, and I do think that strategy is more important under SPAV than under some forms of STV.