Paper: The space of all proportional voting systems and the most majoritarian among them

Abstract: We present an alternative voting system that aims at bridging the gap between pro-portional representative systems and majoritarian electoral systems. The system lets people vote for multiple party lists, but then assigns each ballot paper to a single party. This opens a whole range of possible parliaments, all proportionally representative. We show theoretically that this space is convex. Then among the possible parliamentswe present an algorithm to produce the most majoritarian result. We then test thesystem and compare the results with a pure proportional and a majoritarian votingsystem showing how the results are comparable with the majoritarian system. Then we simulate the system and show how it tends to produce parties of exponentially decreasing size with always a first, major party with about half of the seats. Finally we describe how the system can be used in the context of a parliament made up of twoseparate houses.

The paper was written with my friend and co-author Daniele Gewurz and is available for free from Springer at