This video will explain what Arrow's impossibility theorem is. Named after economist Kenneth J. Arrow, Arrow's impossibility theorem is a social-choice paradox illustrating the impossibility of having an ideal voting structure. Arrow's impossibility theorem says that a clear order of preferences cannot be determined without violating one of the mandatory principles of fair voting procedures. Arrow's impossibility theorem, part of social choice theory, is an economic theory that considers whether a society can be ordered in a way that reflects individual preferences. To see an example of Arrow's impossibility theorem, watch this video.