Electoral threshold

In mixed-member-proportional (MMP) systems, the election threshold determines which parties are eligible for top-up seats in the legislative chamber.

[1] However, others argue that in the absence of a ranked ballot or proportional voting system at the district level, supporters of minor parties, barred from top-up seats, are effectively disenfranchised and denied the right to be represented 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.

Carey and Hix note that increasing the DM past six lowers the natural threshold in the district only in small increments and deceasingly each time.

There are also countries such as Finland, Namibia,[7] North Macedonia, Portugal and South Africa that have proportional representation systems without a legal threshold.

Therefore, the sixth (or, at a double dissolution election, the 12th) Senate seat in each state is often won by a party that received considerably less than the Droop quota in primary votes.

However, this is not a stringent barrier to entry: any party or independent who wins a constituency is entitled to that seat whether or not they have passed the threshold.

Parties representing registered ethnic minorities have no threshold and receive proportional representation should they gain the mathematical minimum number of votes nationally to do so.

[9] This clause has come into effect in two elections: in 1994, when the Party of Democratic Socialism, which had significantly higher support in the former East Germany, won 4.4 percent of party-list votes and four constituencies, and in 2021, when its successor, Die Linke, won 4.9 percent and three constituencies.

However, after complaints from Die Linke and the Christian Social Union, the Federal Constitutional Court ruled a threshold with no exceptions was unconstitutional.

In the United States, as the majority of elections are conducted under the first-past-the-post system, legal electoral thresholds do not apply in the actual voting.

However, several states have threshold requirements for parties to obtain automatic ballot access to the next general election without having to submit voter-signed petitions.

[45] The German Federal Constitutional Court rejected an electoral threshold for the European Parliament in 2011 and in 2014 based on the principle of one person, one vote.

It was justified in the case of Turkey in order to stabilize the volatile political situation over recent decades.

Other factors are the seat allocation formula (Saint-Laguë, D'Hondt or Hare), the number of contestant political parties and the size of the assembly.

Generally, smaller districts leads to a higher proportion of votes needed to win a seat and vice versa.

[59] The lower bound (the threshold of representation or the percentage of the vote that allows a party to earn a seat under the most favorable circumstances) is more difficult to calculate.

In addition to the factors mentioned earlier, the number of votes cast for smaller parties are important.

As a result, Erdoğan's AKP gained power, winning more than two-thirds of the seats in the Parliament with just 34.28 percent of the vote, with only one opposition party (CHP, which by itself failed to pass threshold in 1999) and 9 independents.

Other dramatic events can be produced by the loophole often added in mixed-member proportional representation (used throughout Germany since 1949, New Zealand since 1993): there the threshold rule for party lists includes an exception for parties that won 3 (Germany) or 1 (New Zealand) single-member districts.

The failure of one party to reach the threshold not only deprives their candidates of office and their voters of representation; it also changes the power index in the assembly, which may have dramatic implications for coalition-building.

[79] The justification for such a high threshold was to prevent multi-party coalitions and put a stop to the endless fragmentation of political parties seen in the 1960s and 1970s.

In the Philippines where party-list seats are only contested in 20 percent of the 287 seats in the lower house,[clarification needed] the effect of the 2 percent threshold is increased by the large number of parties participating in the election, which means that the threshold is harder to reach.

For instance, the Turkish AKP won a majority of seats with less than 50 percent of votes in three consecutive elections (2002, 2007 and 2011).

In the 2013 Bavarian state election, the Christian Social Union failed to obtain a majority of votes, but nevertheless won an outright majority of seats due to a record number of votes for parties which failed to reach the threshold, including the Free Democratic Party (the CSU's coalition partner in the previous state parliament).