Prozentschranke

Prozentschranke, in political science, denotes a threshold expressed as a minimum percentage of valid votes that a party must receive to gain seats in a parliament within proportional representation systems. The purpose is to limit party fragmentation and thereby facilitate governability and stable coalitions. Threshold values and rules vary by country and system; common ranges are around 3% to 5%, though some systems use regional thresholds or rely on the electoral formula and district magnitudes to create a de facto barrier.

In practice, Prozentschranke can operate in different forms. A formal national threshold requires parties to surpass a specified share of votes to enter the legislature. Some systems include mechanisms that allow parties to bypass the threshold if they win a minimum number of direct mandates, or seats in single-member districts, even with a lower overall vote share. Germany, for example, uses a 5% nationwide threshold for the Zweitstimme (second vote) to enter the Bundestag, with a Grundmandatsklausel that lets parties win seats if they secure at least three direct mandates. The German system also incorporates overhang- and leveling seats to preserve overall proportionality, which can influence parliament size.

The effects and debate surrounding Prozentschranke center on representational quality versus governability. Supporters argue the threshold reduces fragmentation and simplifies coalition-building; opponents claim it suppresses voter choice, marginalizes small or new parties, and can distort support into wasted votes. Threshold design interacts with district magnitude and apportionment rules, shaping party systems and strategic voting.

See also: electoral threshold, proportional representation, party system.