Discussions regarding raising the parliamentary threshold have resurfaced. The Chairman of the Nasdem Party (February 21, 2026) proposed raising the minimum vote threshold for political parties to secure seats in the House of Representatives to 7 percent. Previously, the Constitutional Court (MK), in its ruling, ordered lawmakers to recalculate the parliamentary threshold for the next election, provided that the proportionality of the election results and the simplification of political parties are maintained. The question is, does the proposal to raise the parliamentary threshold align with the Constitutional Court’s ruling? How should the parliamentary threshold be determined?
Failure to Simplify the Party System
Raising the parliamentary threshold is often seen as a shortcut to simplifying the party system by limiting the number of political parties entering parliament. Since it was first implemented in the 2009 elections, 9 political parties out of a total of 38 participating parties cleared the 2.5 percent parliamentary threshold.
Instead of making it harder for political parties to win seats in the House of Representatives (DPR), raising the parliamentary threshold to 3.5 percent in the 2014 General Election actually led to an increase in the number of political parties in the DPR to 10. The parliamentary threshold was raised again to 4 percent in the 2019 General Election, a level maintained for the 2024 General Election. This increase resulted in the elimination of the Hanura Party from the House of Representatives in the 2019 election and the PPP in the 2024 election.
Reflecting on these four elections, the size of the parliamentary threshold does not always correlate directly with efforts to reduce the number of political parties in the House of Representatives. On the other hand, there has long been a misconception regarding the meaning of simplifying the party system, which is often measured solely by the number of political parties in parliament. In fact, conceptually, a typology of party systems based solely on the number of parties cannot provide a complete explanation of a country’s party system classification.
For example, there were more than 10 political parties in the results of the 2024 UK parliamentary election. Based on numbers alone, the UK should fall into the category of a multiparty system. However, no one claims that the UK adheres to a multiparty system; rather, it is a two-party system. This is because of the total 650 parliamentary seats in the UK, the majority are controlled by two major parties, namely the Labour Party (33.7 percent) and the Conservative Party (23.7 percent). Thus, the number of seats held by political parties in parliament is a more appropriate indicator for classifying party systems.
Laakso and Taagepera (1979) formulated the Effective Number of Parliamentary Parties (ENPP) formula to calculate the weight of political parties in parliament based on the number of seats they hold. The ENPP calculation yields a decimal number indicating the concentration of parliamentary seats distributed across how many political parties. Siaroff (2000) further classified that if the resulting ENPP ranges from 1.92–2.5, it falls into the two-party system category; 2.95–3.69, a moderate/simple multiparty system; and over 3.96, an extreme multiparty system.
ENPP calculations from six DPR elections show that, on average, DPR seats are concentrated among 7 dominant parties, meaning the system falls into the category of an extreme multiparty system. Interestingly, the 1999 election, which did not apply a parliamentary threshold, actually produced an ENPP of 4.7, which is close to a simple multiparty system. Although there were 23 political parties in the House of Representatives, the majority of seats were controlled by 4 dominant parties in the 1999 election.
Proportionality of Election Results
Rather than simplifying the party system, in reality, raising the parliamentary threshold results in disproportionate election outcomes, with a high number of wasted votes. In the 2009 election, 19,047,481 votes were wasted out of a total of 29 political parties that failed to meet the 2.5 percent parliamentary threshold. This number decreased to 2,964,975 in the 2014 election as the number of participating political parties dropped to 12.
However, in the 2019 and 2024 elections, the number of wasted votes increased again as many participating political parties failed to secure the required national valid vote threshold. In the 2019 election, 13,595,842 votes were wasted, and in the 2024 election, 17,304,303 votes were wasted. This means that if the proposed 7 percent parliamentary threshold is applied in the 2029 election, it has the potential to increase the number of wasted votes and would contradict the Constitutional Court’s ruling.
To ensure the proportionality of election results in accordance with the Constitutional Court’s ruling, Taagepera (2002) introduced the effective threshold formula to determine the parliamentary threshold using the equation: 75%(M+1)√E, where M is the average number of seats allocated per electoral district (district magnitude) and E is the total number of electoral districts. Ideally, the parliamentary threshold should be set at 1 percent for the 2024 elections if this formula is used.
This parliamentary threshold may change in tandem with changes in seat allocation and the number of electoral districts. If seat allocation in DPR electoral districts is adjusted (for example, from 3–10 to a minimum of 3 and a maximum of 6 or 8), the parliamentary threshold is likely to increase naturally.
On the other hand, the district magnitude has a strong influence on the simplification of the party system. The smaller the electoral district size, the more difficult it is for political parties to win seats. Thus, this effective threshold formula is highly adaptive for maintaining the proportionality of election results within the framework of simplifying the party system through adjustments to electoral district sizes. []
HEROIK M. PRATAMA
Executive Director of the Association for Elections and Democracy (Perludem)