Gibbard-Satterthwaite theorem

From Electowiki

The Gibbard-Satterthwaite theorem states that every unimposing voting system (one in which every preference order is achievable) which chooses between three or more candidates, must be either dictatorial or manipulable (i.e. susceptible to tactical voting). It follows from Arrow's impossibility theorem. This page is a stub - please add to it. This article is derived from an article on Wikipedia. See its history for list of authors before importation.