Understanding Political Party Systems: Types and Factors

Understanding Political Party Systems

Party systems emerge from parties competing against each other as parts or sections of a social whole, expressing their diversity and differences. The term “party system” refers to the composition of this set and the pattern of relations that hold its components together. These systems are distinguished by the number of parties they contain and the format they adopt.

Factors Explaining the Diversity of Political Parties

  • The existence of partitions or cleavages that express significant differences within a society. Every society defines one or more axes of conflict: the more numerous these are, the more likely the number of parties will increase. Examples of cleavages are the Belgian and Dutch cases.
  • Established rules regulating competition among them. When the electoral system is proportional or distributive, a greater number of parties can win representation. This stimulates the formation of more parties and sustains their existence.

Types of Party Systems

There are four main types of party systems:

  • Dominant Party: Characterized by the existence of a party that continuously gets an absolute majority of votes or stands far ahead of the second-ranked party. This has happened at certain times in the 20th century in Norway and Sweden with the Social Democratic Party.
  • Bipartisan: Defined by a relative balance of power between two major parties, both of which have the probability of obtaining a parliamentary majority and together receive a high percentage of the total vote. The presence of these two parties does not exclude the existence of minor parties with no expectation of becoming the government. The government always corresponds to one of the two major parties. Examples include Great Britain, Canada, the USA, and New Zealand.
  • Multiparty: Reflects a patchy distribution of the vote among several parties, without highlighting the position of the first two.
    • Limited multiparty is when the system contains four or five parties that have some capacity to intervene in the formation of government.
    • Extreme multiparty is when the system contains a greater number of parties.
    Traditionally found in Belgium, the Netherlands, Italy, Switzerland, and Israel, where the formation of a coalition government always requires multiple parties.

Ideological Polarization in Multiparty Systems

Multiparty systems are also categorized according to the distance or ideological polarization that occurs between parties.

  • Polarized Multiparty System: Reveals a wide gap between the parties at the extreme positions on the right-left dimension (Duverger, Sartori). Parties at the extremes of the political spectrum have no chance to participate in a majority government. Competition between parties takes place on a multilateral basis, making majorities of governments and the political system itself very unstable.
  • Moderate Multiparty System: Reflects a situation of ideological and programmatic closeness between all parties as part of the system. They can participate in coalition governments or majorities that support them. Competition takes place mainly in the central area of the political space, where moderate positions are found.