Tuesday, March 24, 2009

A Glossary (For Terril Bouricius)

Like any field, discussion of voting methods has developed a language all its own, full of jargon and technical terms that, while clearly defined for those well-versed in the field, are sometimes confusing or completely opaque to those on the outside. So I don't fault Terril Bouricius for his repeated failures to understand the lingo. I hope he will find this short glossary of voting-method terms useful.

non-mon·o·ton·ic: adj. 1. In reference to a method, a property meaning it is possible in that method to construct a scenario where either a. by improving a winning candidate's rank (or score) on some ballots, the candidate becomes a loser, or b. by lowering a losing candidate's rank (or score) on some ballots, the candidate becomes a winner. 2. In reference to an election, an example where either of the scenarios in 1. is in evidence.

spoi·ler: n. 1. A a non-winning candidate such that, if they are removed from all ballots, the winners of the election change.

By these well-accepted definitions, instant runoff voting is a non-monotonic method (whereas score voting and even plurality are monotonic), and Burlington's recent mayoral election was non-monotonic; instant runoff voting is susceptible to spoilers (plurality is too, but score voting is not), and Kurt Wright was a spoiler for Andy Montroll. These are easily-proven, in-arguable facts, and so are not up for discussion. So please, stop arguing from a position of ignorance, and learn the definitions.


  1. An excellent post. It is mind-boggling that FairVote and friends have the audacity to just completely make things up and "play dumb" in such a manner that one must cite these definitions, which should be elementary knowledge for anyone claiming to have the expertise to be an advocate for a specific voting reform such as IRV. IRV may be better than plurality voting (if extreme care is taken to prevent fraud and other problems that come with its added complexity), but that's certainly no justification for blatantly misinforming the public and denying the reality of the failures IRV experienced in this recent Burlington election.

  2. What bothers me is that there _are_ legitimate complaints one could make about CRV's analysis. For instance, they did make up some preferences in order to claim that Wright voter's would have been happier by not voting (some of the would have, but some of them expressed no preference between Montroll and Kiss, so we can't _really_ say). And one could get into an argument over how important non-monotonic behavior is, or how important spoilers are--and I'd LOVE to see that argument in public--but FairVote stone-walls the issue by denying that they even happened. It's infuriating.