Political parties are ubiquitous across both democratic and autocratic countries, and there is often very little change in which political parties have a chance of holding power in a country from one election to the next. This makes it possible to think about the political parties in a country as collectively forming one of the country's central
political institutions, called a party system. These properties are closely connected to other major features of the country's politics, such as how democratic it is, what sorts of restrictions its laws impose on political parties, and what type of
electoral systems it uses. Even in countries where the number of political parties is not officially constrained by law, political institutions affect how many parties are viable. For example, democracies that use a
single-member district electoral system tend to have very few parties, whereas countries that use
proportional representation tend to have more. The number of parties in a country can also be accurately estimated based on the
magnitude of a country's electoral districts and the number of seats in its legislature.
Non-partisan systems , every member runs and legislates as a political independent with no party affiliation. In a non-partisan system, no political parties exist, or political parties are not a major part of the political system. There are very few
countries without political parties. In some non-partisan countries, the formation of parties is explicitly banned by law. However, parties are also banned in some polities that have long democratic histories, usually in local or regional elections of countries that have strong national party systems. Political parties may also temporarily cease to exist in countries that have either only been established recently, or that have experienced a major upheaval in their politics and have not yet returned to a stable system of political parties. For example, the United States began as a non-partisan democracy, and it evolved a stable system of political parties over the course of many decades. However, it is also possiblealbeit rarefor countries with no bans on political parties, and which have not experienced a major disruption, to nevertheless have no political parties: there are a small number of pacific island democracies, such as
Palau, where political parties are permitted to exist and yet parties are not an important part of national politics.
One-party systems In a
one-party system, power is held entirely by one political party. When only one political party exists, it may be the result of a ban on the formation of any competing political parties, which is a common feature in authoritarian states. For example, the
Communist Party of Cuba is the only permitted political party in
Cuba, and is the only party that can hold seats in the legislature. When only one powerful party is legally permitted to exist, its membership can grow to contain a very large portion of society and it can play substantial roles in
civil society that are not necessarily directly related to political governance; one example of this is the
Chinese Communist Party. Bans on competing parties can also ensure that only one party can ever realistically hold power, even without completely outlawing all other political parties. For example, in
North Korea, more than one party is officially permitted to exist and even to seat members in the legislature, but laws ensure that the
Workers' Party of Korea retains control. It is also possible for countries with free elections to have only one party that holds power. These cases are sometimes called
dominant-party systems or
particracies. Scholars have debated whether or not a country that has never experienced a transfer of power from one party to another can nevertheless be considered a democracy.
Two-party systems In several countries, there are only two parties that have a realistic chance of competing to form government. One current example of a two-party system is the
United States, where the national government has for much of the country's history exclusively been controlled by either the
Democratic Party or the
Republican Party. Other examples of countries which have had long periods of two-party dominance include
Colombia,
Uruguay,
Malta, and
Ghana. Two-party systems are not limited to democracies; they may be present in authoritarian regimes as well. Competition between two parties has occurred in historical autocratic regimes in countries including
Brazil and
Venezuela. A democracy's political institutions can shape the number of parties that it has. In the 1950s Maurice Duverger observed that single-member district single-vote plurality-rule elections tend to produce two-party systems, Some political scientists have broadened this idea to argue that more restrictive political institutions (of which
first past the post is one example) tend to produce a smaller number of political parties, so that extremely small parties systems – like those with only two parties – tend to form in countries with very restrictive rules. Two-party systems have attracted heavy criticism for limiting the choices that electors have, and much of this criticism has centered around their association with restrictive political institutions. For example, some commentators argue that political institutions in prominent two-party systems like the United States have been specifically designed to ensure that no third party can become competitive. Criticisms also center around these systems' tendencies to encourage
insincere voting and to facilitate the
spoiler effect.
Multi-party systems Multi-party systems are systems in which more than two parties have a realistic chance of holding power and influencing policy. and two-party democracies may be considered unusual or uncommon compared to multi-party systems. Many of the
largest democracies in the world have had long periods of multi-party competition, including
India,
Indonesia,
Pakistan, and
Brazil. Multi-party systems encourage characteristically different types of governance than smaller party systems, for example by often encouraging the formation of
coalition governments. The presence of many competing political parties is usually associated with a greater level of democracy, and a country transitioning from having a one-party system to having a many-party system is often considered to be
democratizing. Authoritarian countries can include multi-party competition, but typically this occurs when the elections are
not fair. For this reason, in two-party democracies like the United States, proponents of forming new competitive political parties often argue that developing a multi-party system would make the country more democratic. However, the question of whether multi-party systems are more democratic than two-party systems, or if they enjoy better policy outcomes, is a subject of substantial disagreement among scholars as well as among the public. In the opposite extreme, a country with a very large number of parties can experience governing coalitions that include highly ideologically diverse parties that are unable to make much policy progress, which may cause the country to be unstable and experience a very large number of elections; examples of systems that have been described as having these problems include periods in the recent history of
Israel,
Italy, and
Finland. Multi-party systems are often viewed as fairer or more representative than one- or two-party systems, Some multi-party systems may have two parties that are noticeably more competitive than the other parties. Such party systems have been called "two-party-plus" systems, which refers to the two dominant parties, plus other parties that exist but rarely or never hold power in the government. Such parties may serve a crucial factor in election outcomes. It is also possible for very large multi-party systems, like India's, to nevertheless be characterized largely by a series of regional contests that realistically have only two competitive parties, but in the aggregate can produce many more than two parties that have major roles in the country's national politics. ==Funding==