@ehBeth,
ehBeth wrote:
that isn't mathematical evidence and it's not the on-the-ground reality
Canada sees 3 and 4 parties switch and change lead roles with surprising regularity.
I prefer minority governments by far - a lot more is accomplished when there are minorities. People have to compromise and move things forward in minority governments.
The math is simple enough. Take a US presidential election. Imagine 4 candidates: a leftist liberal, a centrist democrat, a centrist republican, and a tea-party candidate. The sort of things that would happen if the GOP and the democrat party both were to split. Assuming that the US voting population follows a Gauss curve on most issues (=assuming it is not too polarised, which may be assuming too much nowadays but has historically been the case), the two centrist candidates stand a better chance of winning than the two extremists.
Under such a situation, a winning strategy on both sides is to seek compromise and convince the extremist candidate to desist. If, say, the liberal desists from the vote but not the tea party candidate, the centrist democrat will most certainly win because his opposition is divided. So both centrist candidates will try and horse trade with his outlier, eg giving him/her a place on his ticket. This will over time lead politicians to seek broad-based compromises and parties, because division is lethal.
This can be modeled in game theory, which is what I meant by "mathematically proven"... an overstatement for sure.
