Electoral Panorama / Panorama Electoral

Sweden goes to the polls on Sunday, September 17, 2006, to elect members of the country's unicameral legislature - the Riksdag - as well as members of the municipal and county councils.

Riksdag seats (and also municipal and county council seats) are distributed by the adjusted odd-number method of proportional representation, also known as the modified Sainte-Laguë procedure. This system is similar to the d'Hondt rule, but uses as divisors the series 1.4, 3, 5, 7, 9 and so on. Unlike the pure Sainte-Laguë procedure, in which the number one is used as the first divisor, the modified rule increases it to 1.4 to make it more difficult for smaller parties to initially win seats. It should also be noted that the Sainte-Lagüe divisors are in fact the series 0.5 (0.7 for the modified rule), 1.5, 2.5, 3.5, 4.5 and so on, multiplied by two to obtain whole number divisors (save for 1.4).

The modified Sainte-Laguë procedure is also used in legislative elections in Norway and Denmark. Beyond Scandinavia, New Zealand uses the pure Sainte-Laguë rule in parliamentary elections after switching to a proportional representation system in 1993.

Of the 349 Riksdag seats, 310 permanent seats are allocated in twenty-nine multi-member constituencies among parties that have polled at least four percent of the vote on a nationwide basis. In addition, a party that has won less than four percent of the vote in the entire country is entitled to participate in a multi-member constituency's allocation of seats by receiving at least twelve percent of the vote in that constituency.

Although multi-member constituency seats are allocated by proportional representation, this procedure introduces significant variations with respect to the overall distribution of votes. For example, in the 1994 general election, the Social Democratic Party obtained 158 of 310 permanent seats (51%) with 45.3% of the vote, while the Green Party, with five percent of the vote, won only six seats (1.9%). However, the Riksdag has 39 additional seats, known as adjustment seats, whose purpose is to address disparities in the distribution of legislative mandates.

To allocate these seats, all 349 Riksdag seats are distributed on a nationwide basis. Permanent mandates won by a party at the constituency level are then subtracted from its corresponding seat total, and the remaining mandates are filled from the adjustment seats. In 1994, the Social Democratic Party was entitled to a total of 161 seats (46.1%), and therefore it received only three adjustment seats, while the Green Party won a total of 18 mandates (5.2%), of which twelve were adjustment seats. Therefore, adjustment mandates allow for a truly proportional distribution of Riksdag seats.

Adjustment mandates are subsequently allocated at the constituency level on the basis of the largest Sainte-Laguë quotients that have not been used to allocate permanent seats, or the total number of votes polled by a qualifying party in constituencies where it has not obtained any permanent mandates.