Kenneth Arrow Voting Theorem

Kenneth J. Arrow's "Voting Theorem" (also known as "Impossibility Theorem," or sometimes "Voting Paradox," but that can mean other things) says that it is "not possible to create an optimal method of aggregating preferences" (Neil Iscoe) -- that "a perfect voting scheme is a mathematical impossibility." (Jeff Bone)

Here are some references:

"Social Choice and Individual Values," by Kenneth J. Arrow, ISBN:0300013647

http://www.csc.vill.edu/faculty/bartlow/html/mat1220/arrowthm.html http://www.math.vanderbilt.edu/~bruff/voting/arrow.html http://www.dataweb.nl/~cool/Papers/SocialWelfare/Arrow97c.html http://www.faculty.econ.nwu.edu/faculty/witte/pf/handouts/pfvoting.html http://www.nobel.se/economics/laureates/1972/arrow-lecture.pdf