A
multi-party system is a system in which three or more political parties have the capacity to gain control of government separately or in coalition.
Unlike a single-party system (or a
non-partisan democracyNon-partisan democracy is a system of representative government or organization such that universal and periodic elections take place without reference to political parties.-Overview:...
), it encourages the general
constituencyA constituency is any cohesive body of people bound by shared identity, goals, or loyalty. Constituency can be used to describe a business's customer base and shareholders, or a charity's donors or those it serves...
to form multiple distinct, officially recognized groups, generally called
political partiesA political party is a political organization that seeks to attain and maintain political power within government, usually by participating in electoral campaigns...
. Each party competes for votes from the
enfranchisedSuffrage is the civil right to vote, or the exercise of that right. It is also called political franchise or simply the franchise. Suffrage may apply to elections, but also extends to initiatives and referendums...
constituents (those allowed to vote).
A
multi-party system is a system in which three or more political parties have the capacity to gain control of government separately or in coalition.
Unlike a single-party system (or a
non-partisan democracyNon-partisan democracy is a system of representative government or organization such that universal and periodic elections take place without reference to political parties.-Overview:...
), it encourages the general
constituencyA constituency is any cohesive body of people bound by shared identity, goals, or loyalty. Constituency can be used to describe a business's customer base and shareholders, or a charity's donors or those it serves...
to form multiple distinct, officially recognized groups, generally called
political partiesA political party is a political organization that seeks to attain and maintain political power within government, usually by participating in electoral campaigns...
. Each party competes for votes from the
enfranchisedSuffrage is the civil right to vote, or the exercise of that right. It is also called political franchise or simply the franchise. Suffrage may apply to elections, but also extends to initiatives and referendums...
constituents (those allowed to vote). A multi-party system is essential for
representative democraciesElectoral democracies require a majority of the votes cast. Many representative democracies are constitutional republics in which majority rule is tempered by minority rights protected by law".- Criticisms :...
, because it prevents the leadership of a single party from setting
policyA policy is typically described as a deliberate plan of action to guide decisions and achieve rational outcome. However, the term may also be used to denote what is actually done, even though it is unplanned....
without challenge.
If the government includes an elected
CongressA congress is a formal meeting of representatives from different countries , or independent organizations ....
or
ParliamentA parliament is a legislature, especially in those countries whose system of government is based on the Westminster system modeled after that of the United Kingdom. The name is derived from the French parlement, the action of parler : a parlement is a discussion. The term came to mean a meeting at...
the parties may share power according to
Proportional RepresentationProportional representation , sometimes referred to as full representation, is a category of electoral formula aimed at securing a close match between the percentage of votes that groups of candidates obtain in elections and the percentage of seats they receive...
or the First-past-the-post system. In Proportional Representation, each party wins a number of seats proportional to the number of votes it receives. In first-past-the-post, the electorate is divided into a number of districts, each of which selects one person to fill one seat by a plurality of the vote. First-past-the-post is not conducive to a proliferation of parties, and naturally gravitates toward a
two-party systemA two-party system is a form of party system where two major political parties dominate voting in nearly all elections, at every level. As a result, all, or nearly all, elected offices end up being held by candidates endorsed by one of the two major parties...
, in which only two parties have a real chance of electing their candidates to office. This gravitation is known as
Duverger's lawIn political science, Duverger's law is a principle which asserts that a plurality rule election system tends to favor a two-party system. This is one of two hypotheses proposed by Duverger, the second stating that “The double ballot majority system and proportional representation tend to...
. Proportional Representation, on the other hand, does not have this tendency, and allows multiple major parties to arise.
This difference is not without implications. A two-party system requires voters to align themselves in large blocs, sometimes so large that they cannot agree on any overarching principles. Along this line of thought, some theories argue that this allows
centristIn politics, centrism is the ideal or the practice of promoting moderate policies which lie between different political extremes. Most commonly, this is visualized as part of the one-dimensional political spectrum of left-right politics, with centrism landing in the middle between left-wing...
s to gain control. On the other hand, if there are multiple major parties, each with less than a majority of the vote, the parties are forced to work together to form working governments. This also promotes a form of centrism.
The
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
is an example of where there may be a multi-party system but that only two parties have ever formed government in the last 150 years.
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
,
IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
,
IndonesiaThe Republic of Indonesia is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With an estimated population of around 237 million people, it is the world's fourth most populous country, with the world's largest population of Muslims.Indonesia is a republic, with an...
,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
, and
IsraelIsrael officially the State of Israel , is a developed state in Western Asia located on the eastern shore of the Mediterranean Sea. It borders Lebanon in the north, Syria in the northeast, Jordan in the east, and Egypt on the southwest, and contains geographically diverse features within its...
are examples of nations that have used a multi-party system effectively in their democracies (though in each case there are two parties larger than all others, even though most of the time no party has a parliamentary majority by itself). In these nations, multiple political parties have often formed
coalitionA coalition is an alliance among individuals or groups, during which they cooperate in joint action, each in his own self-interest, joining forces together for a common cause. This alliance may be temporary or a matter of convenience. A coalition thus differs from a more formal covenant...
s for the purpose of developing power blocs for governing.