Denmark[edit]

In 1915, Denmark became one of the first countries in the world to introduce leveling seats in their parliamentary elections. Since then, all parliamentary elections in Denmark have allocated these adjustment seats as a substantial fraction of the seats in the parliament. The parliamentary seats currently comprise 135 county seats and 40 leveling seats, with a further 4 "North Atlantic seats" elected separately by proportional representation in the Faroe Islands and Greenland (which are not treated as an integral part of the Danish election system). The leveling seats are supplementary to the normal seats which are allocated by proportional votes within each county. All parties which achieve at least 2% of the national votes are granted as many leveling seats as required to achieve proportional representation at the national level.[2]

Iceland[edit]

Leveling seats have been a part of the election procedures for all Icelandic parliamentary elections since 1934.[3]

In order to be eligible for leveling seats, a party must get at least 4% (the exclusion threshold) of the national popular vote. A party may attain enough votes in a given county to elect a representative but may fail to be eligible for leveling seats.

The number of representatives elected per county is a function of the total population in the county and the area of the county. Hence, the county of needs fewer votes to elect a representative (7,409 in 2005) than Oslo (18,167 the same election).

Finnmark

Of 169 representatives, 150 are elected by popular vote within the county. This means that a party that achieves 40% of the popular vote in a county will send about 40% of the total number of representatives from that county.

The remaining 19 representatives are allocated one to each county but are elected based on nationwide results for a party, as long as the popular vote at the national level for that party exceeds the exclusion threshold of 4%. The result is that each representative represents an approximately equal number of voters.

Germany[edit]

In February 2013, following a decision of the Federal Constitutional Court which demanded a reform of the electoral law for proportional representation, Germany added a provision to create national leveling seats as needed in a case of negative vote weight occurring in its mixed member proportional system, in addition to the traditional leveling seats that already existed in many state elections.[9]

Additional Member System

Biproportional apportionment

Mixed-member proportional representation