Concept
A party system is a concept in comparative political science concerning the system of government by political parties in a democratic country. The idea is that political parties have basic similarities: they control the government, have a stable base of mass popular support, and create internal mechanisms for controlling funding, information and nominations. The party system concept was originated by European scholars studying the United States, especially James Bryce, Giovanni Sartori and Moisey Ostrogorsky, and has been expanded to cover other democracies. Party systems can be distinguished by the degree of political fragmentation, proportionality of seats-to-votes ratio and barriers to entry to the political competition. One-party system: a system in which a single political party has the right to form the government, usually based on the existing constitution, or where only one party has the exclusive control over political power. Example: China Dominant-party system: a system where there is "a category of parties/political organizations that have successively won election victories and whose future defeat cannot be envisaged or is unlikely for the foreseeable future". Example: Russia Two party system: a system where only two parties or alliances, typically placed either side of the center, have a realistic chance of forming a majority. Other parties are very minor or solely regional. Example: United States, United Kingdom Multi-party system: a system in which multiple political parties have the capacity to gain control of government offices, separately or in coalition. Example: Sweden, Ireland Non-partisan system: a system of government or organization such that universal and periodic elections take place without reference to political parties. Example: Micronesia Democratic party systems in most European states have increasingly fragmented over time. That means that the number of relevant parties surged, while the average size declined. Hence, the effective number of parties increased.