A Majoritarian Representative Voting System

Pietro Speroni di Fenizio, Daniele Gewurz:
A Majoritarian Representative Voting System
in COMSOC, 22 June 2016

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We present an alternative voting system that aims at bridging the gap between proportional representative systems and majoritarian, single winner election systems. The system lets people vote for multiple parties, but then assignes each ballot to a single party. This opens a whole range of possible systems, all representative. We show theoretically that this space is convex. Then among the possible parliaments we present an algorithm to produce the most majoritarian result.

We then test the system and compare the results with a pure proportional and a majoritarian voting system showing how the results are comparable with the ma- joritarian system. Then we simulate the system and show how it tends to produce parties of exponentially decreasing size with always a first, major party.

Finally we describe how the system can be used in a context of a parliament made up of two separate houses.