Electoral threshold

The electoral threshold is the minimum share of the vote which a political party requires to secure any representation in a legislature. This limit can operate in various ways. For example, in party-list proportional representation systems, an election threshold requires that a party must receive a specified minimum percentage of votes (e.g. 5%), either nationally or within a particular district, to obtain any seats in the parliament. If there are a number of multi-member constituencies, each constituency will have a quota, i.e. a minimum percentage of the votes in that constituency to be awarded one seat.

The effect of an electoral threshold is to deny representation to small parties or to force them into coalitions, with the presumption of rendering the election system more stable by keeping out radical factions. However, critics point out that in the absence of a ranked ballot system supporters of minor parties are effectively disenfranchised and denied the right of representation by someone of their choosing.

Two boundaries can be defined: a threshold of representation is the minimum vote share that might yield a party a seat (under the most favorable circumstances for the party), while the threshold of exclusion is the maximum vote share that could be insufficient to yield a seat (under the least favorable circumstances). Lijphart suggested calculating the informal threshold as the mean of these.

In Poland's Sejm, Germany's Bundestag and New Zealand's House of Representatives, the threshold is 5%. However, in Germany and New Zealand, if a party wins a minimum number of directly elected seats—three in Germany and one in New Zealand—the threshold does not apply (though the directly elected seats are kept regardless). The threshold is 3.25% in Israel's Knesset (it was 1% before 1992, 1.5% in 1992–2003 and 2% until March 2014), and 10% in the Turkish parliament. In Poland, ethnic minority parties do not have to reach the threshold level to get into the parliament, and so there is always a small German minority representation in the Sejm. In Romania, for the ethnic minority parties there is a different threshold than for the national parties that run for the Chamber of Deputies.

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