Ranked ballots allow a voter to express relative preferences among candidates. For example, a ranked ballot of A>B>C indicates that the voter prefers candidate A to candidate B, candidate B to candidate C and (thus) candidate A to candidate C.
Here I describe and compare several methods of choosing a single winner given a collection of ranked ballots. The methods vary in their ability to choose a candidate with broad appeal (to satify “social utility”) and to resist strategically insincere voting. (Unfortunately, no ranked-ballot voting method is entirely resistant to such insincerity, unlike better and simpler systems such as Approval Voting.)
I never quite got around to finishing this project to my satisfaction—it’s still a work in progress—but please browse around, see what you think, and e-mail any comments, criticisms, or suggestions to firstname.lastname@example.org. The ranked-ballot voting calculator is especially useful and fun to experiment with.