New Zealanders will vote in a referendum in November asking whether they want to change the current voting system used for deciding the makeup of Parliament.

Dr Geoffrey Pritchard and Dr Mark C. Wilson, members of the Centre for Mathematical Social Science at the University of Auckland, have created a simulator intended to voters to compare the 5 proposed electoral systems in a quantitative way, by allowing them to compute quickly, for a given polling scenario, the party seat distribution in Parliament under each system. It is written in Javascript and the source code is publicly available.

The authors intend to refine the model used in future depending on resources, and welcome constructive feedback. The simulator is a research tool that they hope will have some use for members of the public.

The simulator can be accessed here.