Election threshold
From Freepedia
In party-list proportional representation systems, an election threshold is a clause that stipulates that a party must receive a minimum percentage of votes, either nationally or within a particular district, to get any seats in the parliament. The effect of the threshold is to eliminate small parties, or force them into coalitions. Many people hold that this makes an election system more stable by keeping out radical factions.
In Poland's Sejm and Germany's Bundestag (elected through the Additional member system), this threshold is 5% (or 3 constituency seats in Bundestag, but directly won constituencies are kept regardlessly), while it's 2% in Israel's Knesset (it was 1% before 1992 and 1.5% from 1992-2003), and 10% in the Turkish parliament. In Poland, the minorities do not have to reach the threshold level to get into the parliament, and so there are 2 MP from German Minority in the Sejm.
Countries can have more than one threshold. For example, Germany, as mentioned earlier, has a "regular" threshold of 5%, but if 3 constituency seats are won in the Bundestag, the party can get additional representation with less than 5% of the vote. Most multiple-thresholds are still in the proposal stage. For example, in Canada, one proposal to reform the electoral system would see a 5% national threshold, 1% of the vote and 1 seat in the house of commons, or 2% nationally and 15% of the vote in any one province.
Election thresholds are often implemented with the intention of bringing stability to the political system. However, electoral thresholds can sometimes seriously affect the relation between percentual election results and seat distribution. A striking example is Turkey. The 10% threshold in Turkey was established mainly to prevent multi-party coalitions and put an hold the endless fragmentation of political parties as seen in '60s and '70s. However, coalitions ruled between 1991 and 2002, mainstream parties continued to be fragmented and as a serious side effect, the 2002 elections caused 45% of the votes casted for below-threshold parties to be unrepresented in the parliament. Because of these reasons some people feel the side effects of election thresholds are worse than the problems they counter.
Election thresholds cause spoiler effect same as Single non-transferable vote, where minor parties who can't overcome thresholds takes votes away from chance of change proportion of partie's seats to wasted vote. The common desire among voters to avoid this problem inevitably leads to the distortion of tactical voting same as Duverger's law, sometimes leading to a situation where a fossil party who has no supporter left gets seats instead of newcomer party whose supporter and leader misunderstands (Misunderstands? No, because his(her) prospect will come true if (s)he avoids wasted vote which means not vote his(her) party.) his(her) party can't overcome thresholds yet.
