Comment by notriddle | Hacker News Reader

Comment by notriddle | Hacker News Reader

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> The problem with cardinal systems is that political parties will tell their followers "just vote 10.0 for me and 0.0 for everyone else".

Of course parties will try to convince people to do that. The question is whether voters will listen.

It's extremely easy to prove to yourself that, if my ranked preferences are O'TruePreference is better than Doe who is better than McBadGuy, then this ballot:

    Evil McBadGuy: 0
    John Doe 10.0
    Andre O'TruePreference 10.0

... is strictly better than this one, regardless of how other people vote:

    Evil McBadGuy: 0
    John Doe 10.0
    Andre O'TruePreference 0

> Enough people will do that to obviate the other advantages.

I know this happened with Approval Voting, but that doesn't necessarily mean it'll happen to Score Voting. It's likely that voters just didn't read the directions, and thought that if they voted for more than one candidate their ballot would be discarded.

Yeah, this is called "bullet voting" (for those that don't know). It is often brought up as a killer strategy to cardinal systems but it really isn't that bad. No system is immune to strategies and I think people just find one strategy and disregard a system because they found a flaw. Social choice is over constrained. There are trade-offs and local optimizations but no global optimization. We can't talk about voting systems without acknowledging this point.

To be clear, bullet voting in Score is equivalent to Approval Voting. AV still has a lot of advantages over Runoff Voting.

> It's likely that voters just didn't read the directions

This is actually a point (that I don't bring up much because it is minor) that I prefer cardinal over ranked. It is much easier to mess up a ranked ballot than cardinal. Give the same score to multiple candidates? No problem. In a ranked ballot you have issues and no good resolutions (toss ballot, flip a coin on preference and then reorder? Both of which can be called voter manipulation, despite them not really being). These issues arise more as the system scales too.

The big killer to me (besides the information embedding) is the tallying (backend that voters don't see). Cardinal systems are just an argmax reduce-sum (trivially parallelizable). Trivial to calculate and do statistical samples/verification on. This is a lot harder with run-off systems. The multi-elections required actually takes a lot of man power. Just think about how recounts like Arizona would happen under Cardinal vs Ordinal. This is something people really have to consider when accounting for voting systems. There is a front end and back end but most people argue front end + a few cherry picked strategies.

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