Norway elections for the Storting (unicameral government chamber) use party-list proportional representation in nineteen multi-member districts. There are compensatory levelling seats, one in each district.
The number of members returned from each constituency ranges from 4 to 19.
Scientific Districting
The apportionment of the 169 seats amongst the 19 districts (each one of which is a county), is determiend by a a two-tier formula based on population and geographic size. Each inhabitant counts one point, while each square kilometer counts 1.8 points.[19]
The system for apportioning seats is biased in favour of rural areas since the area of the county is a factor, but the system of compensation seats reduces the effect this has on final party strength
Levelling seats
A total of 150 of the seats are regular district seats. These are awarded based on the election results in each county, and are unaffected by results in other counties.
Nineteen of the seats (one ineach county) are levelling seats, awarded to parties who win fewer regular seats in the counties than their share of the national popular vote otherwise entitles them to.
A modification of the Sainte-Lague method, where the first quotient for each party is calculated using a divisor of 1.4 instead of 1, is used to allocate both the constituency and levelling seats.
A party must win 4 percent of the popular vote in order to win compensation seats. The threshold has no effect on the regular district seats.
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