The mechanisms are economic in nature if you assume the context of a first past the post electoral system.
It's worth repeating that FPTP maximizes the number of those who are discontented: Parties lose all incentives to appeal to more than 50%+1, so the remaining 49.9% are left high and dry. This implies that a proportional representation system will be more stable, because a higher percentage of the voters will be represented.
It's worth repeating that FPTP maximizes the number of those who are discontented: Parties lose all incentives to appeal to more than 50%+1, so the remaining 49.9% are left high and dry. This implies that a proportional representation system will be more stable, because a higher percentage of the voters will be represented.