Copeland method .2. Manipulation, monotonicity, and paradoxes

An important issue for economics and the decision sciences is to understand why allocation and decision procedures are plagued by manipulative and paradoxical behavior once there are n greater than or equal to 3 alternatives. Valuable insight is obtained by exploiting the relative simplicity of the widely used Copeland method (CM). By using a geometric approach, we characterize all CM manipulation, monotonicity, consistency, and involvement properties while identifying all profiles which are susceptible to these difficulties. For instance, we show for n = 3 candidates that the CM minimizes the negative aspects of the Gibbard-Satterthwaite theorem. (C) 1997 Academic Press.