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Approval voting collapses to FPTP once the parties tell their voters "just mark one box". This is an unavoidable vulnerability in any scheme that doesn't invol

Approval voting collapses to FPTP once the parties tell their voters "just mark one box". This is an unavoidable vulnerability in any scheme that doesn't involve an exhaustive and exlusive ranking.

Epenthesis 8y ago
Why would the voters listen to them if they did in fact approve of multiple candidates?
- mtgx 8y ago
  For the same reason they don't vote for a third-party candidate in the general, even if they like that candidate much more - they want to maximize the chance of winning for the "lesser evil" and not risk the "greater evil" winning. I do like approval voting as well, for the same mentioned reasons, but I worry that after a few elections people would start voting strategically, and then it could take another few decades to change the voting system again. The more important part isn't ranked choice or approval voting anyway - both are single-winner voting systems which are far from ideal for elections involving Congress/Parliaments and local legislature. It's much preferable to have a proportional representation voting system for those.
  - CarVac 8y ago
    How is there any increased risk of "greater evil" winning from third party voting in approval voting?
    - jacques_chester 8y ago
      You may safely rely on both the greater evil and lesser evils saying so.
      - dllthomas 8y ago
        Maybe. But it should be less effective when it's obviously bullshit than when there's at least a kernel of truth.
- jacques_chester 8y ago
  First, because the parties will say "don't risk your vote!" and deliberately muddy the waters. Second, because in a voluntary voting situation the voter population is dominated by partisans, who are more motivated to vote. This isn't a hypothetical. Queensland introduced "optional" preferential voting and one of the majors promptly campaigned on "Just Vote 1" in order to wedge the opposing coalition.
  - harshreality 8y ago
    GP was talking about approval voting. What Queensland uses, (which they call) Preferential voting, is IRV (instant-runoff voting). That's not approval voting. It might initially seem like IRV's ranking (A>B>C>D>E) would be a better voting system than Approval Voting (where voters simply say A-yes, B-yes, others-no). Relative rankings seem at first glance to express more information. But it turns out that the way you have to count relative rankings either leads to pathological consequences for 3rd parties (see IRV), just like winner-takes-all voting, or the counting method becomes complex and byzantine in corner cases (see Condorcet). It's all explained on rangevoting.org
    - jacques_chester 8y ago
      I am aware of the difference between IRV and approval voting. I am pointing out that there are examples in the wild of non-exhaustive systems being exploited. Approval is non-exhaustive by design, but even in a system where exhaustiveness had been the norm for decades a single political party in a single election was able to substantially regress its performance.
      - deleted 8y ago
        [deleted]
    - dragonwriter 8y ago
      > Preferential voting is IRV. Most real and proposed balloting methods (other than range/score voting) are preferential, they differ in the restrictions on he expressed preferences; IRV (and lots of other systems), as usually defined, relies on a fully-ranked forced-preference (no ties) ballot. Approval has an implicitly fully-ranked two-preference-rank ballot with unlimited ties, FPTP (whether plurality or majority/runoff) has an implicitly fully-ranked two-preference-rank ballot with ties allowed only in the second rank. > Relative rankings seem to express more information They do, there is no “seem". They also do so more consistently. Forced preferences can have the reverse problem of forced ties, though (which is abstractly a point in favor of unforced ranking ballots, but there's less work done on resolution procedures for them.) > but it turns out that the way you have to count relative rankings either leads to pathological consequences for 3rd parties (see IRV), just like winner-takes-all voting, or the counting method becomes complex and byzantine in corner cases (see Condorcet). Bucklin is simpler to count than IRV and doesn't have it's pathological effects; the main concrete criticism I've seen is that if truncation is allowed rather than forced-preference, and if the no-majority fallback is highest-vote-total-on-last-round, it may encourage truncation and devolve to plurality. (But a similar charge of incentive to bullet-vote is made against approval.)
- dragonwriter 8y ago
  > Why would the voters listen to them if they did in fact approve of multiple candidates? What does “approve of multiple candidates” even mean? Preferring one candidate over another has a clear meaning. Approval does not; as well as meaning honest, uninfluenced ballots are going to vary from voter to voter even with the same actual assessment of candidates, that makes it a lot easier for voters to be manipulated by influencers as to the right way to map preferences to ballot markings. Approval is good for open-ballot voting on, e.g, where to go to lunch (where “approve” means “commit to attend if the option is chosen”.) It's a poor choice for public, secret-ballot elections.
  - CarVac 8y ago
    Approval doesn't have to mean the same thing for everyone.
    - dragonwriter 8y ago
      > Approval doesn't have to mean the same thing for everyone. If it doesn't, then your ballots have no consistent meaning and any process for aggregating them produces garbage output in terms of aggregating social preference. Consistency of meaning of ballot markings and the resolution process being sensible in terms of that meaning are the most critical minimal standards for a voting system. Otherwise, voting is a farce and distraction, not a serious way of guaranteeing that government is accountable.
      - ben_w 8y ago
        That problem already exists.
        dragonwriter 8y ago
        Arguably, sure, that's one characterization of the problem alternative voting systems seek to solve. That isn't a reason to choose a system that maximizes the degree to which that problem is preserved.
      - 8y ago
carry_bit 8y ago
People understand the current system well, so the new system collapsing to it isn't that bad.
kragen 8y ago
It's okay if some voters decide to throw away 90% of their vote by approval-voting for one candidate instead of, say, 10 candidates. If half of the voters do that, while the other half vote rationally, then the voters who voted more rationally will have cast 91% of the votes in the election, and the voters who decided to "Just Vote 1" will be almost irrelevant, except in a close choice between two broadly-appealing candidates. In approval voting, the strategy to maximize the influence of your vote is to vote for half of the candidates, or at least half of the candidates who are likely to win. (Well, except that arguably in nearly all election schemes, the instrumentally rational strategy is to stay home and do something productive, like baking a pie, having sex, or writing some software; this is why voting is obligatory in nearly all functioning democracies.)

Approval voting collapses to FPTP once the parties tell their voters "just mark one box". This is an unavoidable vulnerability in any scheme that doesn't involve an exhaustive and exlusive ranking.

Epenthesis 8y ago

Why would the voters listen to them if they did in fact approve of multiple candidates?

mtgx 8y ago
For the same reason they don't vote for a third-party candidate in the general, even if they like that candidate much more - they want to maximize the chance of winning for the "lesser evil" and not risk the "greater evil" winning. I do like approval voting as well, for the same mentioned reasons, but I worry that after a few elections people would start voting strategically, and then it could take another few decades to change the voting system again. The more important part isn't ranked choice or approval voting anyway - both are single-winner voting systems which are far from ideal for elections involving Congress/Parliaments and local legislature. It's much preferable to have a proportional representation voting system for those.
- CarVac 8y ago
  How is there any increased risk of "greater evil" winning from third party voting in approval voting?
  - jacques_chester 8y ago
    You may safely rely on both the greater evil and lesser evils saying so.
    - dllthomas 8y ago
      Maybe. But it should be less effective when it's obviously bullshit than when there's at least a kernel of truth.
jacques_chester 8y ago
First, because the parties will say "don't risk your vote!" and deliberately muddy the waters. Second, because in a voluntary voting situation the voter population is dominated by partisans, who are more motivated to vote. This isn't a hypothetical. Queensland introduced "optional" preferential voting and one of the majors promptly campaigned on "Just Vote 1" in order to wedge the opposing coalition.
- harshreality 8y ago
  GP was talking about approval voting. What Queensland uses, (which they call) Preferential voting, is IRV (instant-runoff voting). That's not approval voting. It might initially seem like IRV's ranking (A>B>C>D>E) would be a better voting system than Approval Voting (where voters simply say A-yes, B-yes, others-no). Relative rankings seem at first glance to express more information. But it turns out that the way you have to count relative rankings either leads to pathological consequences for 3rd parties (see IRV), just like winner-takes-all voting, or the counting method becomes complex and byzantine in corner cases (see Condorcet). It's all explained on rangevoting.org
  - jacques_chester 8y ago
    I am aware of the difference between IRV and approval voting. I am pointing out that there are examples in the wild of non-exhaustive systems being exploited. Approval is non-exhaustive by design, but even in a system where exhaustiveness had been the norm for decades a single political party in a single election was able to substantially regress its performance.
    - deleted 8y ago
      [deleted]
  - dragonwriter 8y ago
    > Preferential voting is IRV. Most real and proposed balloting methods (other than range/score voting) are preferential, they differ in the restrictions on he expressed preferences; IRV (and lots of other systems), as usually defined, relies on a fully-ranked forced-preference (no ties) ballot. Approval has an implicitly fully-ranked two-preference-rank ballot with unlimited ties, FPTP (whether plurality or majority/runoff) has an implicitly fully-ranked two-preference-rank ballot with ties allowed only in the second rank. > Relative rankings seem to express more information They do, there is no “seem". They also do so more consistently. Forced preferences can have the reverse problem of forced ties, though (which is abstractly a point in favor of unforced ranking ballots, but there's less work done on resolution procedures for them.) > but it turns out that the way you have to count relative rankings either leads to pathological consequences for 3rd parties (see IRV), just like winner-takes-all voting, or the counting method becomes complex and byzantine in corner cases (see Condorcet). Bucklin is simpler to count than IRV and doesn't have it's pathological effects; the main concrete criticism I've seen is that if truncation is allowed rather than forced-preference, and if the no-majority fallback is highest-vote-total-on-last-round, it may encourage truncation and devolve to plurality. (But a similar charge of incentive to bullet-vote is made against approval.)
dragonwriter 8y ago
> Why would the voters listen to them if they did in fact approve of multiple candidates? What does “approve of multiple candidates” even mean? Preferring one candidate over another has a clear meaning. Approval does not; as well as meaning honest, uninfluenced ballots are going to vary from voter to voter even with the same actual assessment of candidates, that makes it a lot easier for voters to be manipulated by influencers as to the right way to map preferences to ballot markings. Approval is good for open-ballot voting on, e.g, where to go to lunch (where “approve” means “commit to attend if the option is chosen”.) It's a poor choice for public, secret-ballot elections.
- CarVac 8y ago
  Approval doesn't have to mean the same thing for everyone.
  - dragonwriter 8y ago
    > Approval doesn't have to mean the same thing for everyone. If it doesn't, then your ballots have no consistent meaning and any process for aggregating them produces garbage output in terms of aggregating social preference. Consistency of meaning of ballot markings and the resolution process being sensible in terms of that meaning are the most critical minimal standards for a voting system. Otherwise, voting is a farce and distraction, not a serious way of guaranteeing that government is accountable.
    - ben_w 8y ago
      That problem already exists.
      - dragonwriter 8y ago
        Arguably, sure, that's one characterization of the problem alternative voting systems seek to solve. That isn't a reason to choose a system that maximizes the degree to which that problem is preserved.
    - 8y ago

carry_bit 8y ago

People understand the current system well, so the new system collapsing to it isn't that bad.

kragen 8y ago

It's okay if some voters decide to throw away 90% of their vote by approval-voting for one candidate instead of, say, 10 candidates. If half of the voters do that, while the other half vote rationally, then the voters who voted more rationally will have cast 91% of the votes in the election, and the voters who decided to "Just Vote 1" will be almost irrelevant, except in a close choice between two broadly-appealing candidates. In approval voting, the strategy to maximize the influence of your vote is to vote for half of the candidates, or at least half of the candidates who are likely to win. (Well, except that arguably in nearly all election schemes, the instrumentally rational strategy is to stay home and do something productive, like baking a pie, having sex, or writing some software; this is why voting is obligatory in nearly all functioning democracies.)