Borda and Plurality Comparison with Regard to Compromise as a Sorites Paradox

Abstract

Social choice decision aggregation is a form of complex system modelling which is based upon voters’ rankings over a set of candidates. Different social choice functions, such as Borda count, plurality count or Condorcet methods models different aspects of social choice decision criteria. One of such criteria which has not been fully described or modelled, is the notion of compromise. This article aims to define a measure which would capture the notion of compromise on a given profile of voter preferences, about certain candidate being appointed to a certain position by a certain social welfare function. The goal is to define what compromise should mean, and proposes the so called “d measure of divergence” as a measure of divergence for some candidate to be positioned to a certain position. This study compares the results of two well established social welfare functions, Borda and plurality count d-measure of divergence.

Keywords

• Borda count
• plurality count
• compromise