Eleições paradoxiais

“Rational” in this context simply means consistent or transitive preferences: If you prefer X to Y, and Y to Z, you will also prefer X to Z. The Condorcet paradox says that even with rational electors, a majority that prefers X to Y and Y to Z can prefer Z to X.

Read more: http://www.fee.org/the_freeman/detail/the-paradox-of-voting#ixzz2mSt4PGDl