Approval voting system (Executive summary)

  1. Approval voting is the special case of range voting where each score must be the maximum or the minimum (intermediate scores forbidden).
  2. So range voting offers more expressivity to voters than Approval voting.
  3. "Honest" voters tend to want to take advantage of that extra expressivity, but "strategic" voters don't.
  4. So in situations with a lot of voter honesty, range voting will produce better results than approval voting, whereas in situations dominated by strategic voters, range and approval voting will deliver the same election results.
  5. That is the reason why range voting experimentally delivers much better Bayesian Regret than approval voting if the voters are honest. Borda voting also is far superior to approval if the voters are honest (more superior the more candidates there are), but Borda is far worse with strategic voters. With range voting we get the best of both worlds – as good performance as approval with strategic voters (indeed even a bit better), and also even better performance than Borda with honest voters.
  6. Experimentally (and surprisingly to many), considerable honesty is common (about 75%) among range voters in US presidential elections. Therefore range voting should deliver results far superior to approval results in important real-world elections.
  7. Approval voting is simpler than range voting, but the better results we get from range voting (e.g. better US presidents) are well worth the small cost of that extra complexity. Also, on many kinds of voting machines (and this also is surprising to many people, but true) both range and approval appear very easy to the voter. Try demo. Both range and approval voting are usable on every voting machine in the USA, including noncomputerized ones, right now, without modification and without reprogramming (also surprising, but true).
  8. Due to the (enormous) nursery effect, range voting is much more likely than approval voting to allow third parties to survive and grow.
  9. Range voting is much less likely to lead to a tie than approval voting. (The Brams-Hansen-Orrison paper describes an approval-voting election that reached an exact tie, but with range voting there almost certainly would not have been a tie.)
  10. Range voting is much less likely than approval to lead to backsliding to plurality voting (such as the IEEE's backslide). Why adopt a voting system if that improvement will just get revoked later?
  11. Approval voting is subject to a problem which Nagel dubbed Burr's dilemma. Range voting is less subject to that problem.
  12. We recommend approval voting in situations where simplicity and speed are paramount (manual votes in large meetings). We also recommend approval voting as a temporary stopgap measure, ultimately to be replaced with range voting, in situations where the voting machines are such that approval is much easier for the voter than range. (The two can be scaled to coexist in the same election.)
  13. But we recommend range in situations where the quality of the election results are more important than the minor cost of increased complexity of range voting – i.e, most situations.

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