|Main index||Electoral System index||About author| Julian D. A.
Wiseman Abstract: Under PR-Squared there are ‘stable’ outcomes
with three parties, probably not with four, and definitely not
with five or more. Publication history: only at
www.jdawiseman.com/papers/electsys/pr2_three_parties.html. Usual
disclaimer and copyright terms apply. Contents: Summary; Three
parties; Four parties; Five parties; Tiny parties. PR-Squared is
a new electoral system originally designed for the UK’s House of
Commons. It is described at
www.jdawiseman.com/papers/electsys/pr2.html, and the PR-Squared
outcome for the UK’s May 2010 election is discussed at
www.jdawiseman.com/papers/electsys/pr2_uk_201005.html. It is
assumed that readers are familiar with at least one of these
essays. How many serious parties there would be under PR-
Squared? This essay explains that there are stable three-party
outcomes, but with four parties the incentive to form pre-
election coalitions becomes powerful, and for five or more
parties becomes overwh