A new perspective on implementation by voting trees

Voting trees describe an iterative procedure for selecting a single vertex from a tournament. vide a very general abstract model of decision-making among a group of individuals, and it has therefore been studied which voting rules have a tree that implements them, i.e., chooses according to the rule for every tournament. While partial results concerning implementable rules and necessary conditions for implementability have been obtained over the past forty years, a complete characterization of voting rules implementable by trees has proven surprisingly hard to find. A prominent rule that cannot be implemented by trees is the Copeland rule, which singles out vertices with maximum degree. In this paper, we suggest a new angle of attack and re-examine the implementability of the Copeland solution using paradigms and techniques that are at the core of theoretical computer science. We study the extent to which voting trees can approximate the maximum degree in a tournament, and give upper...

• Type: Conference
• Year: 2009
• Where: SIGECOM
• Authors: Felix A. Fischer, Ariel D. Procaccia, Alex Samorodnitsky
• Keywords: General Abstract Model, Information Management, Maximum Degree, SIGECOM 2009, Single Vertex