One of the questions that keeps me from jumping on the STV bandwagon is the issue of complexity. It seems reasonable to hypothesize that the harder it is to see how your votes affect the outcome, the less likely you are to see your vote as effective… and to cast a ballot.
The answer I’ve heard from STV’s supporters has been to not worry; as one put it to me, “It’s not like you know how your DVD player works.” True. On the other hand, I know that if I put Finding Nemo in my DVD player, Finding Nemo is what plays on my TV screen… and not, say, Kill Bill: Vol. 2.
Does anyone know if there’s been research on STV’s impact on voter turnout and feelings of voter efficacy?
Hello Rob, studies I don’t have and yes STV does eliminate almost all strategic or tactical voting. But, on the other hand, it lets people vote for something rather than often voting against. If you vote for someone who has no chance, then your second choice comes in and your vote is transferred, so vote “splitting” becomes an outdated concept as well.
Those are definitely advantages (although for people who want to vote against someone, there’s a certain visceral satisfaction in ranking them waaaaay at the bottom). I’m more wondering about the formulas used in distributing transferred votes, which is the question that people who are wondering about STV usually raise with me; the explanations I’ve seen for those tend to be pretty long, complex and opaque.
That arises particularly because, as I understand it, STV doesn’t eliminate tactical voting. How you rank the candidates you don’t support can influence the outcome, potentially as much as how you rank those you do. But the algebra behind how that works is, so far, beyond me…
ahhh…the formulas…best I can do is ask if you have seen the animation on the citizen assembly web site:
http://www.citizensassembly.bc.ca/flash/bc-stv-count
There are some subtleties hiding in there, yes, but they’re very small effects. Similarly, while it is *possible* for the rankings you assign far down-ticket to affect the outcome, their effect is reduced by the algebra to the point where it’s no longer meaningful.
The easiest way to explain it is to think about actually writing on each ballot. What you write is “this ballot is worth X% of its original value.” The only way it can drop in value is to have the ballot actually elect someone; if a ballot’s worth a third of its original value, that’s because two-thirds has already put someone(s) into office this election.
So after someone is elected – say with twice as many votes as he needed to do so – the votes that elected him aren’t gone. Instead, because we had twice as many as we needed, we write on all of them “this ballot is worth 50% of its original value.” Then we transfer the ballots to their next available target. Down the road let’s say that someone gets elected with 1.5x as many votes as he needs, including some of these ballots. To elect this candidate uses up 66.7% of each vote, leaving 33.3% of whatever value they had before. The ones that were already worth only 50% of a vote are now worth 33.3% x 50% = 16.7% of their original value. The rest of their strength has all been spent on electing candidates.
The only reason why your ballot might eventually not use up all 100% of its strength to elect people is because it had no remaining valid targets. Either because you didn’t mark preferences that far down the ticket, or because the preferences still on it have already been elected. (In some other systems votes for already-elected candidates would get transferred to them, end up as a surplus, and get transferred off again; BC-STV uses the simpler system where if Bob is already in office, we skip over Bob anytime his name comes up later in the count, and go to the next name on that ballot’s list.)
Sometimes it can help to give “value” a specific metaphor. Each ballot comes with 100 golden frogs. It takes 5000 frogs to get elected. If 100 people rank someone first, that’s 10,000 frogs – twice as many as we need – so they each chip in 50 frogs and that candidate is in. Their ballots, with 50 frogs left, go to the next person on the list.